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[FFmpeg-devel] avformat/fifo_test: Move into tests/fifo_muxer.c

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Series [FFmpeg-devel] avformat/fifo_test: Move into tests/fifo_muxer.c | expand

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Commit Message

Andreas Rheinhardt March 12, 2024, 6:43 p.m. UTC 
This muxer solely exists to test the fifo muxer via a dedicated
test tool in libavformat/tests/fifo_muxer.c. It fulfills no
other role and it is only designed with this role in mind.

The latter can be seen in two facts: The muxer uses printf
for logging and it simply presumes the packets' data to contain
a FailingMuxerPacketData (a struct duplicated in fifo_test.c
and tests/fifo_muxer.c.); in particular, it presumes packets
to have data at all, but this need not be true with side-data
only packets and a segfault can easily be triggered by e.g.
encoding flac (our native encoder sends a side-data only packet
with updated extradata at the end of encoding).

This patch fixes this by moving the test muxer into the fifo
test tool, making it inaccessible via the API (and actually
removing it from libavformat.so and libavformat.a).
While this muxer was accessible via e.g. av_guess_format(),
it was not really usable for an API user as FailingMuxerPacketData
was not public. Therefore this is not considered a breaking change.

In order to continue to use the test muxer in the test tool,
the ordinary fifo muxer had to be overridden: fifo_muxer.c
includes lavf/fifo.c but with FIFO_TEST defined which makes
it support the fifo_test muxer. This is possible because
test tools are always linked statically to their respective
library.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
---
Will I have to bump minor when applying this?

 libavformat/Makefile           |   1 -
 libavformat/allformats.c       |   1 -
 libavformat/fifo.c             |   7 ++
 libavformat/fifo_test.c        | 157 ---------------------------------
 libavformat/tests/fifo_muxer.c | 126 +++++++++++++++++++++++++-
 5 files changed, 132 insertions(+), 160 deletions(-)
 delete mode 100644 libavformat/fifo_test.c

Comments

Stefano Sabatini March 12, 2024, 8:20 p.m. UTC | #1 
On date Tuesday 2024-03-12 19:43:29 +0100, Andreas Rheinhardt wrote:
> This muxer solely exists to test the fifo muxer via a dedicated
> test tool in libavformat/tests/fifo_muxer.c. It fulfills no
> other role and it is only designed with this role in mind.
> 
> The latter can be seen in two facts: The muxer uses printf
> for logging and it simply presumes the packets' data to contain
> a FailingMuxerPacketData (a struct duplicated in fifo_test.c
> and tests/fifo_muxer.c.); in particular, it presumes packets
> to have data at all, but this need not be true with side-data
> only packets and a segfault can easily be triggered by e.g.
> encoding flac (our native encoder sends a side-data only packet
> with updated extradata at the end of encoding).
> 
> This patch fixes this by moving the test muxer into the fifo
> test tool, making it inaccessible via the API (and actually
> removing it from libavformat.so and libavformat.a).
> While this muxer was accessible via e.g. av_guess_format(),
> it was not really usable for an API user as FailingMuxerPacketData
> was not public. Therefore this is not considered a breaking change.
> 
> In order to continue to use the test muxer in the test tool,
> the ordinary fifo muxer had to be overridden: fifo_muxer.c
> includes lavf/fifo.c but with FIFO_TEST defined which makes
> it support the fifo_test muxer. This is possible because
> test tools are always linked statically to their respective
> library.
> 
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
> ---

> Will I have to bump minor when applying this?

Given that this is a fix, probably a micro bump is enough.

> 
>  libavformat/Makefile           |   1 -
>  libavformat/allformats.c       |   1 -
>  libavformat/fifo.c             |   7 ++
>  libavformat/fifo_test.c        | 157 ---------------------------------
>  libavformat/tests/fifo_muxer.c | 126 +++++++++++++++++++++++++-
>  5 files changed, 132 insertions(+), 160 deletions(-)
>  delete mode 100644 libavformat/fifo_test.c
> 
> diff --git a/libavformat/Makefile b/libavformat/Makefile
> index 785349c036..94a949f555 100644
> --- a/libavformat/Makefile
> +++ b/libavformat/Makefile
> @@ -205,7 +205,6 @@ OBJS-$(CONFIG_EPAF_DEMUXER)              += epafdec.o pcm.o
>  OBJS-$(CONFIG_FFMETADATA_DEMUXER)        += ffmetadec.o
>  OBJS-$(CONFIG_FFMETADATA_MUXER)          += ffmetaenc.o
>  OBJS-$(CONFIG_FIFO_MUXER)                += fifo.o
> -OBJS-$(CONFIG_FIFO_TEST_MUXER)           += fifo_test.o
>  OBJS-$(CONFIG_FILMSTRIP_DEMUXER)         += filmstripdec.o
>  OBJS-$(CONFIG_FILMSTRIP_MUXER)           += filmstripenc.o rawenc.o
>  OBJS-$(CONFIG_FITS_DEMUXER)              += fitsdec.o
> diff --git a/libavformat/allformats.c b/libavformat/allformats.c
> index 5639715104..e15d0fa6d7 100644
> --- a/libavformat/allformats.c
> +++ b/libavformat/allformats.c
> @@ -165,7 +165,6 @@ extern const FFOutputFormat ff_f4v_muxer;
>  extern const FFInputFormat  ff_ffmetadata_demuxer;
>  extern const FFOutputFormat ff_ffmetadata_muxer;
>  extern const FFOutputFormat ff_fifo_muxer;
> -extern const FFOutputFormat ff_fifo_test_muxer;
>  extern const FFInputFormat  ff_filmstrip_demuxer;
>  extern const FFOutputFormat ff_filmstrip_muxer;
>  extern const FFInputFormat  ff_fits_demuxer;
> diff --git a/libavformat/fifo.c b/libavformat/fifo.c
> index a3d41ba0d3..2a2673f4d8 100644
> --- a/libavformat/fifo.c
> +++ b/libavformat/fifo.c
> @@ -528,6 +528,13 @@ static int fifo_init(AVFormatContext *avf)
>      atomic_init(&fifo->queue_duration, 0);
>      fifo->last_sent_dts = AV_NOPTS_VALUE;
>  

> +#ifdef FIFO_TEST
> +    /* This exists for the fifo_muxer test tool. */
> +    if (fifo->format && !strcmp(fifo->format, "fifo_test")) {
> +        extern const FFOutputFormat ff_fifo_test_muxer;
> +        oformat = &ff_fifo_test_muxer.p;
> +    } else
> +#endif

I see, but as unrelated note, it seems odd we don't have a register
API to add a custom muxer/demuxer, and having to go through this dance
is not really viable at the application level. That's why I wonder why
we don't have such API (I remember it was available at some point).

Anyway this hack is still better than keeping the fifo_test publicly
available.

>      oformat = av_guess_format(fifo->format, avf->url, NULL);
>      if (!oformat) {
>          ret = AVERROR_MUXER_NOT_FOUND;
> diff --git a/libavformat/fifo_test.c b/libavformat/fifo_test.c
> deleted file mode 100644
> index 3861c4aee4..0000000000
> --- a/libavformat/fifo_test.c
> +++ /dev/null
> @@ -1,157 +0,0 @@
> -/*
> - * FIFO test pseudo-muxer
> - * Copyright (c) 2016 Jan Sebechlebsky
> - *
> - * This file is part of FFmpeg.
> - *
> - * FFmpeg is free software; you can redistribute it and/or
> - * modify it under the terms of the GNU Lesser General Public License
> - * as published by the Free Software Foundation; either
> - * version 2.1 of the License, or (at your option) any later version.
> - *
> - * FFmpeg is distributed in the hope that it will be useful,
> - * but WITHOUT ANY WARRANTY; without even the implied warranty of
> - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> - * GNU Lesser General Public License for more details.
> - *
> - * You should have received a copy of the GNU Lesser General Public License
> - * along with FFmpeg; if not, write to the Free Software * Foundation, Inc.,
> - * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> - */
> -
> -#include <stdlib.h>
> -
> -#include "libavutil/opt.h"
> -#include "libavutil/time.h"
> -
> -#include "avformat.h"
> -#include "mux.h"
> -#include "url.h"
> -
> -/* Implementation of mock muxer to simulate real muxer failures */
> -
> -#define MAX_TST_PACKETS 128
> -#define SLEEPTIME_50_MS 50000
> -#define SLEEPTIME_10_MS 10000
> -
> -/* Implementation of mock muxer to simulate real muxer failures */
> -
> -/* This is structure of data sent in packets to
> - * failing muxer */
> -typedef struct FailingMuxerPacketData {
> -    int ret;             /* return value of write_packet call*/
> -    int recover_after;   /* set ret to zero after this number of recovery attempts */
> -    unsigned sleep_time; /* sleep for this long in write_packet to simulate long I/O operation */
> -} FailingMuxerPacketData;
> -
> -
> -typedef struct FailingMuxerContext {
> -    AVClass *class;
> -    int write_header_ret;
> -    int write_trailer_ret;
> -    /* If non-zero, summary of processed packets will be printed in deinit */
> -    int print_deinit_summary;
> -
> -    int flush_count;
> -    int pts_written[MAX_TST_PACKETS];
> -    int pts_written_nr;
> -} FailingMuxerContext;
> -
> -static int failing_write_header(AVFormatContext *avf)
> -{
> -    FailingMuxerContext *ctx = avf->priv_data;
> -    return ctx->write_header_ret;
> -}
> -
> -static int failing_write_packet(AVFormatContext *avf, AVPacket *pkt)
> -{
> -    FailingMuxerContext *ctx = avf->priv_data;
> -    int ret = 0;
> -    if (!pkt) {
> -        ctx->flush_count++;
> -    } else {
> -        FailingMuxerPacketData *data = (FailingMuxerPacketData*) pkt->data;
> -
> -        if (!data->recover_after) {
> -            data->ret = 0;
> -        } else {
> -            data->recover_after--;
> -        }
> -
> -        ret = data->ret;
> -
> -        if (data->sleep_time) {
> -            int64_t slept = 0;
> -            while (slept < data->sleep_time) {
> -                if (ff_check_interrupt(&avf->interrupt_callback))
> -                    return AVERROR_EXIT;
> -                av_usleep(SLEEPTIME_10_MS);
> -                slept += SLEEPTIME_10_MS;
> -            }
> -        }
> -
> -        if (!ret) {
> -            ctx->pts_written[ctx->pts_written_nr++] = pkt->pts;
> -            av_packet_unref(pkt);
> -        }
> -    }
> -    return ret;
> -}
> -
> -static int failing_write_trailer(AVFormatContext *avf)
> -{
> -    FailingMuxerContext *ctx = avf->priv_data;
> -    return ctx->write_trailer_ret;
> -}
> -
> -static void failing_deinit(AVFormatContext *avf)
> -{
> -    int i;
> -    FailingMuxerContext *ctx = avf->priv_data;
> -
> -    if (!ctx->print_deinit_summary)
> -        return;
> -
> -    printf("flush count: %d\n", ctx->flush_count);
> -    printf("pts seen nr: %d\n", ctx->pts_written_nr);
> -    printf("pts seen: ");
> -    for (i = 0; i < ctx->pts_written_nr; ++i ) {
> -        printf(i ? ",%d" : "%d", ctx->pts_written[i]);
> -    }
> -    printf("\n");
> -}
> -#define OFFSET(x) offsetof(FailingMuxerContext, x)
> -static const AVOption options[] = {
> -        {"write_header_ret", "write_header() return value", OFFSET(write_header_ret),
> -         AV_OPT_TYPE_INT, {.i64 = 0}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
> -        {"write_trailer_ret", "write_trailer() return value", OFFSET(write_trailer_ret),
> -         AV_OPT_TYPE_INT, {.i64 = 0}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
> -        {"print_deinit_summary", "print summary when deinitializing muxer", OFFSET(print_deinit_summary),
> -         AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM},
> -        {NULL}
> -    };
> -
> -static const AVClass failing_muxer_class = {
> -    .class_name = "Fifo test muxer",
> -    .item_name  = av_default_item_name,
> -    .option     = options,
> -    .version    = LIBAVUTIL_VERSION_INT,
> -};
> -
> -const FFOutputFormat ff_fifo_test_muxer = {
> -    .p.name         = "fifo_test",
> -    .p.long_name    = NULL_IF_CONFIG_SMALL("Fifo test muxer"),
> -    .priv_data_size = sizeof(FailingMuxerContext),
> -    .write_header   = failing_write_header,
> -    .write_packet   = failing_write_packet,
> -    .write_trailer  = failing_write_trailer,
> -    .deinit         = failing_deinit,
> -    .p.priv_class   = &failing_muxer_class,
> -#if FF_API_ALLOW_FLUSH
> -    .p.flags        = AVFMT_NOFILE | AVFMT_ALLOW_FLUSH,
> -#else
> -    .p.flags        = AVFMT_NOFILE,
> -#endif
> -    .flags_internal = FF_FMT_ALLOW_FLUSH,
> -};
> -
> diff --git a/libavformat/tests/fifo_muxer.c b/libavformat/tests/fifo_muxer.c
> index 11a557c1a0..34aaa55326 100644
> --- a/libavformat/tests/fifo_muxer.c
> +++ b/libavformat/tests/fifo_muxer.c
> @@ -23,8 +23,20 @@
>  #include "libavutil/opt.h"
>  #include "libavutil/time.h"
>  #include "libavformat/avformat.h"
> +#include "libavformat/mux.h"
>  #include "libavformat/url.h"
> -#include "libavformat/network.h"
> +
> +/*
> + * Include fifo.c directly to override libavformat/fifo.c and
> + * thereby prevent libavformat/fifo.o from being pulled in when linking.
> + * This relies on libavformat always being linked statically to its
> + * test tools (like this one).
> + * Due to FIFO_TEST, our fifo muxer will include special handling
> + * for tests, i.e. it allows to select the fifo_test muxer below
> + * even though it is not accessible via the API.
> + */
> +#define FIFO_TEST
> +#include "libavformat/fifo.c"
>  
>  #define MAX_TST_PACKETS 128
>  #define SLEEPTIME_50_MS 50000

> @@ -38,6 +50,118 @@ typedef struct FailingMuxerPacketData {
>      unsigned sleep_time; /* sleep for this long in write_packet to simulate long I/O operation */
>  } FailingMuxerPacketData;

nit: FifoTestMuxerPacketData

>  
> +typedef struct FifoTestMuxerContext {
> +    AVClass *class;
> +    int write_header_ret;
> +    int write_trailer_ret;
> +    /* If non-zero, summary of processed packets will be printed in deinit */
> +    int print_deinit_summary;
> +
> +    int flush_count;
> +    int pts_written[MAX_TST_PACKETS];
> +    int pts_written_nr;
> +} FifoTestMuxerContext;
> +

> +static int failing_write_header(AVFormatContext *avf)

nit: while at it let's use a more sensible prefix, failing => fifo_test

> +{
> +    FifoTestMuxerContext *ctx = avf->priv_data;
> +    return ctx->write_header_ret;
> +}
> +
> +static int failing_write_packet(AVFormatContext *avf, AVPacket *pkt)
> +{
> +    FifoTestMuxerContext *ctx = avf->priv_data;
> +    int ret = 0;
> +    if (!pkt) {
> +        ctx->flush_count++;
> +    } else {
> +        FailingMuxerPacketData *data = (FailingMuxerPacketData*) pkt->data;
> +
> +        if (!data->recover_after) {
> +            data->ret = 0;
> +        } else {
> +            data->recover_after--;
> +        }
> +
> +        ret = data->ret;
> +
> +        if (data->sleep_time) {
> +            int64_t slept = 0;
> +            while (slept < data->sleep_time) {
> +                if (ff_check_interrupt(&avf->interrupt_callback))
> +                    return AVERROR_EXIT;
> +                av_usleep(SLEEPTIME_10_MS);
> +                slept += SLEEPTIME_10_MS;
> +            }
> +        }
> +
> +        if (!ret) {
> +            ctx->pts_written[ctx->pts_written_nr++] = pkt->pts;
> +            av_packet_unref(pkt);
> +        }
> +    }
> +    return ret;
> +}
> +
> +static int failing_write_trailer(AVFormatContext *avf)
> +{
> +    FifoTestMuxerContext *ctx = avf->priv_data;
> +    return ctx->write_trailer_ret;
> +}
> +
> +static void failing_deinit(AVFormatContext *avf)
> +{
> +    int i;
> +    FifoTestMuxerContext *ctx = avf->priv_data;
> +
> +    if (!ctx->print_deinit_summary)
> +        return;
> +
> +    printf("flush count: %d\n", ctx->flush_count);
> +    printf("pts seen nr: %d\n", ctx->pts_written_nr);
> +    printf("pts seen: ");
> +    for (i = 0; i < ctx->pts_written_nr; ++i ) {
> +        printf(i ? ",%d" : "%d", ctx->pts_written[i]);
> +    }
> +    printf("\n");
> +}
> +
> +#define OFF(x) offsetof(FifoTestMuxerContext, x)
> +static const AVOption fifo_test_options[] = {
> +        {"write_header_ret", "write_header() return value", OFF(write_header_ret),
> +         AV_OPT_TYPE_INT, {.i64 = 0}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
> +        {"write_trailer_ret", "write_trailer() return value", OFF(write_trailer_ret),
> +         AV_OPT_TYPE_INT, {.i64 = 0}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
> +        {"print_deinit_summary", "print summary when deinitializing muxer", OFF(print_deinit_summary),
> +         AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM},
> +        {NULL}
> +    };
> +
> +static const AVClass failing_muxer_class = {
> +    .class_name = "Fifo test muxer",
> +    .item_name  = av_default_item_name,
> +    .option     = fifo_test_options,
> +    .version    = LIBAVUTIL_VERSION_INT,
> +};
> +
> +const FFOutputFormat ff_fifo_test_muxer = {
> +    .p.name         = "fifo_test",
> +    .p.long_name    = NULL_IF_CONFIG_SMALL("Fifo test muxer"),
> +    .priv_data_size = sizeof(FifoTestMuxerContext),
> +    .write_header   = failing_write_header,
> +    .write_packet   = failing_write_packet,
> +    .write_trailer  = failing_write_trailer,
> +    .deinit         = failing_deinit,
> +    .p.priv_class   = &failing_muxer_class,
> +#if FF_API_ALLOW_FLUSH
> +    .p.flags        = AVFMT_NOFILE | AVFMT_ALLOW_FLUSH,
> +#else
> +    .p.flags        = AVFMT_NOFILE,
> +#endif
> +    .flags_internal = FF_FMT_ALLOW_FLUSH,

> +};
> +
> +

nit++++: drop double empty line

>  static int prepare_packet(AVPacket *pkt, const FailingMuxerPacketData *pkt_data, int64_t pts)
>  {
>      int ret = av_new_packet(pkt, sizeof(*pkt_data));
> -- 
> 2.40.1

LGTM, thanks.
Andreas Rheinhardt March 12, 2024, 8:25 p.m. UTC | #2 
Stefano Sabatini:
> On date Tuesday 2024-03-12 19:43:29 +0100, Andreas Rheinhardt wrote:
>> This muxer solely exists to test the fifo muxer via a dedicated
>> test tool in libavformat/tests/fifo_muxer.c. It fulfills no
>> other role and it is only designed with this role in mind.
>>
>> The latter can be seen in two facts: The muxer uses printf
>> for logging and it simply presumes the packets' data to contain
>> a FailingMuxerPacketData (a struct duplicated in fifo_test.c
>> and tests/fifo_muxer.c.); in particular, it presumes packets
>> to have data at all, but this need not be true with side-data
>> only packets and a segfault can easily be triggered by e.g.
>> encoding flac (our native encoder sends a side-data only packet
>> with updated extradata at the end of encoding).
>>
>> This patch fixes this by moving the test muxer into the fifo
>> test tool, making it inaccessible via the API (and actually
>> removing it from libavformat.so and libavformat.a).
>> While this muxer was accessible via e.g. av_guess_format(),
>> it was not really usable for an API user as FailingMuxerPacketData
>> was not public. Therefore this is not considered a breaking change.
>>
>> In order to continue to use the test muxer in the test tool,
>> the ordinary fifo muxer had to be overridden: fifo_muxer.c
>> includes lavf/fifo.c but with FIFO_TEST defined which makes
>> it support the fifo_test muxer. This is possible because
>> test tools are always linked statically to their respective
>> library.
>>
>> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
>> ---
> 
>> Will I have to bump minor when applying this?
> 
> Given that this is a fix, probably a micro bump is enough.
> 
>>
>>  libavformat/Makefile           |   1 -
>>  libavformat/allformats.c       |   1 -
>>  libavformat/fifo.c             |   7 ++
>>  libavformat/fifo_test.c        | 157 ---------------------------------
>>  libavformat/tests/fifo_muxer.c | 126 +++++++++++++++++++++++++-
>>  5 files changed, 132 insertions(+), 160 deletions(-)
>>  delete mode 100644 libavformat/fifo_test.c
>>
>> diff --git a/libavformat/Makefile b/libavformat/Makefile
>> index 785349c036..94a949f555 100644
>> --- a/libavformat/Makefile
>> +++ b/libavformat/Makefile
>> @@ -205,7 +205,6 @@ OBJS-$(CONFIG_EPAF_DEMUXER)              += epafdec.o pcm.o
>>  OBJS-$(CONFIG_FFMETADATA_DEMUXER)        += ffmetadec.o
>>  OBJS-$(CONFIG_FFMETADATA_MUXER)          += ffmetaenc.o
>>  OBJS-$(CONFIG_FIFO_MUXER)                += fifo.o
>> -OBJS-$(CONFIG_FIFO_TEST_MUXER)           += fifo_test.o
>>  OBJS-$(CONFIG_FILMSTRIP_DEMUXER)         += filmstripdec.o
>>  OBJS-$(CONFIG_FILMSTRIP_MUXER)           += filmstripenc.o rawenc.o
>>  OBJS-$(CONFIG_FITS_DEMUXER)              += fitsdec.o
>> diff --git a/libavformat/allformats.c b/libavformat/allformats.c
>> index 5639715104..e15d0fa6d7 100644
>> --- a/libavformat/allformats.c
>> +++ b/libavformat/allformats.c
>> @@ -165,7 +165,6 @@ extern const FFOutputFormat ff_f4v_muxer;
>>  extern const FFInputFormat  ff_ffmetadata_demuxer;
>>  extern const FFOutputFormat ff_ffmetadata_muxer;
>>  extern const FFOutputFormat ff_fifo_muxer;
>> -extern const FFOutputFormat ff_fifo_test_muxer;
>>  extern const FFInputFormat  ff_filmstrip_demuxer;
>>  extern const FFOutputFormat ff_filmstrip_muxer;
>>  extern const FFInputFormat  ff_fits_demuxer;
>> diff --git a/libavformat/fifo.c b/libavformat/fifo.c
>> index a3d41ba0d3..2a2673f4d8 100644
>> --- a/libavformat/fifo.c
>> +++ b/libavformat/fifo.c
>> @@ -528,6 +528,13 @@ static int fifo_init(AVFormatContext *avf)
>>      atomic_init(&fifo->queue_duration, 0);
>>      fifo->last_sent_dts = AV_NOPTS_VALUE;
>>  
> 
>> +#ifdef FIFO_TEST
>> +    /* This exists for the fifo_muxer test tool. */
>> +    if (fifo->format && !strcmp(fifo->format, "fifo_test")) {
>> +        extern const FFOutputFormat ff_fifo_test_muxer;
>> +        oformat = &ff_fifo_test_muxer.p;
>> +    } else
>> +#endif
> 
> I see, but as unrelated note, it seems odd we don't have a register
> API to add a custom muxer/demuxer, and having to go through this dance
> is not really viable at the application level. That's why I wonder why
> we don't have such API (I remember it was available at some point).
> 

The reason is that this would complicate changing the internals of
(de)muxers.

> Anyway this hack is still better than keeping the fifo_test publicly
> available.
> 
>>      oformat = av_guess_format(fifo->format, avf->url, NULL);
>>      if (!oformat) {
>>          ret = AVERROR_MUXER_NOT_FOUND;
>> diff --git a/libavformat/fifo_test.c b/libavformat/fifo_test.c
>> deleted file mode 100644
>> index 3861c4aee4..0000000000
>> --- a/libavformat/fifo_test.c
>> +++ /dev/null
>> @@ -1,157 +0,0 @@
>> -/*
>> - * FIFO test pseudo-muxer
>> - * Copyright (c) 2016 Jan Sebechlebsky
>> - *
>> - * This file is part of FFmpeg.
>> - *
>> - * FFmpeg is free software; you can redistribute it and/or
>> - * modify it under the terms of the GNU Lesser General Public License
>> - * as published by the Free Software Foundation; either
>> - * version 2.1 of the License, or (at your option) any later version.
>> - *
>> - * FFmpeg is distributed in the hope that it will be useful,
>> - * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> - * GNU Lesser General Public License for more details.
>> - *
>> - * You should have received a copy of the GNU Lesser General Public License
>> - * along with FFmpeg; if not, write to the Free Software * Foundation, Inc.,
>> - * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
>> - */
>> -
>> -#include <stdlib.h>
>> -
>> -#include "libavutil/opt.h"
>> -#include "libavutil/time.h"
>> -
>> -#include "avformat.h"
>> -#include "mux.h"
>> -#include "url.h"
>> -
>> -/* Implementation of mock muxer to simulate real muxer failures */
>> -
>> -#define MAX_TST_PACKETS 128
>> -#define SLEEPTIME_50_MS 50000
>> -#define SLEEPTIME_10_MS 10000
>> -
>> -/* Implementation of mock muxer to simulate real muxer failures */
>> -
>> -/* This is structure of data sent in packets to
>> - * failing muxer */
>> -typedef struct FailingMuxerPacketData {
>> -    int ret;             /* return value of write_packet call*/
>> -    int recover_after;   /* set ret to zero after this number of recovery attempts */
>> -    unsigned sleep_time; /* sleep for this long in write_packet to simulate long I/O operation */
>> -} FailingMuxerPacketData;
>> -
>> -
>> -typedef struct FailingMuxerContext {
>> -    AVClass *class;
>> -    int write_header_ret;
>> -    int write_trailer_ret;
>> -    /* If non-zero, summary of processed packets will be printed in deinit */
>> -    int print_deinit_summary;
>> -
>> -    int flush_count;
>> -    int pts_written[MAX_TST_PACKETS];
>> -    int pts_written_nr;
>> -} FailingMuxerContext;
>> -
>> -static int failing_write_header(AVFormatContext *avf)
>> -{
>> -    FailingMuxerContext *ctx = avf->priv_data;
>> -    return ctx->write_header_ret;
>> -}
>> -
>> -static int failing_write_packet(AVFormatContext *avf, AVPacket *pkt)
>> -{
>> -    FailingMuxerContext *ctx = avf->priv_data;
>> -    int ret = 0;
>> -    if (!pkt) {
>> -        ctx->flush_count++;
>> -    } else {
>> -        FailingMuxerPacketData *data = (FailingMuxerPacketData*) pkt->data;
>> -
>> -        if (!data->recover_after) {
>> -            data->ret = 0;
>> -        } else {
>> -            data->recover_after--;
>> -        }
>> -
>> -        ret = data->ret;
>> -
>> -        if (data->sleep_time) {
>> -            int64_t slept = 0;
>> -            while (slept < data->sleep_time) {
>> -                if (ff_check_interrupt(&avf->interrupt_callback))
>> -                    return AVERROR_EXIT;
>> -                av_usleep(SLEEPTIME_10_MS);
>> -                slept += SLEEPTIME_10_MS;
>> -            }
>> -        }
>> -
>> -        if (!ret) {
>> -            ctx->pts_written[ctx->pts_written_nr++] = pkt->pts;
>> -            av_packet_unref(pkt);
>> -        }
>> -    }
>> -    return ret;
>> -}
>> -
>> -static int failing_write_trailer(AVFormatContext *avf)
>> -{
>> -    FailingMuxerContext *ctx = avf->priv_data;
>> -    return ctx->write_trailer_ret;
>> -}
>> -
>> -static void failing_deinit(AVFormatContext *avf)
>> -{
>> -    int i;
>> -    FailingMuxerContext *ctx = avf->priv_data;
>> -
>> -    if (!ctx->print_deinit_summary)
>> -        return;
>> -
>> -    printf("flush count: %d\n", ctx->flush_count);
>> -    printf("pts seen nr: %d\n", ctx->pts_written_nr);
>> -    printf("pts seen: ");
>> -    for (i = 0; i < ctx->pts_written_nr; ++i ) {
>> -        printf(i ? ",%d" : "%d", ctx->pts_written[i]);
>> -    }
>> -    printf("\n");
>> -}
>> -#define OFFSET(x) offsetof(FailingMuxerContext, x)
>> -static const AVOption options[] = {
>> -        {"write_header_ret", "write_header() return value", OFFSET(write_header_ret),
>> -         AV_OPT_TYPE_INT, {.i64 = 0}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
>> -        {"write_trailer_ret", "write_trailer() return value", OFFSET(write_trailer_ret),
>> -         AV_OPT_TYPE_INT, {.i64 = 0}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
>> -        {"print_deinit_summary", "print summary when deinitializing muxer", OFFSET(print_deinit_summary),
>> -         AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM},
>> -        {NULL}
>> -    };
>> -
>> -static const AVClass failing_muxer_class = {
>> -    .class_name = "Fifo test muxer",
>> -    .item_name  = av_default_item_name,
>> -    .option     = options,
>> -    .version    = LIBAVUTIL_VERSION_INT,
>> -};
>> -
>> -const FFOutputFormat ff_fifo_test_muxer = {
>> -    .p.name         = "fifo_test",
>> -    .p.long_name    = NULL_IF_CONFIG_SMALL("Fifo test muxer"),
>> -    .priv_data_size = sizeof(FailingMuxerContext),
>> -    .write_header   = failing_write_header,
>> -    .write_packet   = failing_write_packet,
>> -    .write_trailer  = failing_write_trailer,
>> -    .deinit         = failing_deinit,
>> -    .p.priv_class   = &failing_muxer_class,
>> -#if FF_API_ALLOW_FLUSH
>> -    .p.flags        = AVFMT_NOFILE | AVFMT_ALLOW_FLUSH,
>> -#else
>> -    .p.flags        = AVFMT_NOFILE,
>> -#endif
>> -    .flags_internal = FF_FMT_ALLOW_FLUSH,
>> -};
>> -
>> diff --git a/libavformat/tests/fifo_muxer.c b/libavformat/tests/fifo_muxer.c
>> index 11a557c1a0..34aaa55326 100644
>> --- a/libavformat/tests/fifo_muxer.c
>> +++ b/libavformat/tests/fifo_muxer.c
>> @@ -23,8 +23,20 @@
>>  #include "libavutil/opt.h"
>>  #include "libavutil/time.h"
>>  #include "libavformat/avformat.h"
>> +#include "libavformat/mux.h"
>>  #include "libavformat/url.h"
>> -#include "libavformat/network.h"
>> +
>> +/*
>> + * Include fifo.c directly to override libavformat/fifo.c and
>> + * thereby prevent libavformat/fifo.o from being pulled in when linking.
>> + * This relies on libavformat always being linked statically to its
>> + * test tools (like this one).
>> + * Due to FIFO_TEST, our fifo muxer will include special handling
>> + * for tests, i.e. it allows to select the fifo_test muxer below
>> + * even though it is not accessible via the API.
>> + */
>> +#define FIFO_TEST
>> +#include "libavformat/fifo.c"
>>  
>>  #define MAX_TST_PACKETS 128
>>  #define SLEEPTIME_50_MS 50000
> 
>> @@ -38,6 +50,118 @@ typedef struct FailingMuxerPacketData {
>>      unsigned sleep_time; /* sleep for this long in write_packet to simulate long I/O operation */
>>  } FailingMuxerPacketData;
> 
> nit: FifoTestMuxerPacketData
> 

This would necessitate changes to the part of the test tool that I did
not change and would therefore need to be a commit of its own. I can do
this, of course.

>>  
>> +typedef struct FifoTestMuxerContext {
>> +    AVClass *class;
>> +    int write_header_ret;
>> +    int write_trailer_ret;
>> +    /* If non-zero, summary of processed packets will be printed in deinit */
>> +    int print_deinit_summary;
>> +
>> +    int flush_count;
>> +    int pts_written[MAX_TST_PACKETS];
>> +    int pts_written_nr;
>> +} FifoTestMuxerContext;
>> +
> 
>> +static int failing_write_header(AVFormatContext *avf)
> 
> nit: while at it let's use a more sensible prefix, failing => fifo_test
> 

Ok.

>> +{
>> +    FifoTestMuxerContext *ctx = avf->priv_data;
>> +    return ctx->write_header_ret;
>> +}
>> +
>> +static int failing_write_packet(AVFormatContext *avf, AVPacket *pkt)
>> +{
>> +    FifoTestMuxerContext *ctx = avf->priv_data;
>> +    int ret = 0;
>> +    if (!pkt) {
>> +        ctx->flush_count++;
>> +    } else {
>> +        FailingMuxerPacketData *data = (FailingMuxerPacketData*) pkt->data;
>> +
>> +        if (!data->recover_after) {
>> +            data->ret = 0;
>> +        } else {
>> +            data->recover_after--;
>> +        }
>> +
>> +        ret = data->ret;
>> +
>> +        if (data->sleep_time) {
>> +            int64_t slept = 0;
>> +            while (slept < data->sleep_time) {
>> +                if (ff_check_interrupt(&avf->interrupt_callback))
>> +                    return AVERROR_EXIT;
>> +                av_usleep(SLEEPTIME_10_MS);
>> +                slept += SLEEPTIME_10_MS;
>> +            }
>> +        }
>> +
>> +        if (!ret) {
>> +            ctx->pts_written[ctx->pts_written_nr++] = pkt->pts;
>> +            av_packet_unref(pkt);
>> +        }
>> +    }
>> +    return ret;
>> +}
>> +
>> +static int failing_write_trailer(AVFormatContext *avf)
>> +{
>> +    FifoTestMuxerContext *ctx = avf->priv_data;
>> +    return ctx->write_trailer_ret;
>> +}
>> +
>> +static void failing_deinit(AVFormatContext *avf)
>> +{
>> +    int i;
>> +    FifoTestMuxerContext *ctx = avf->priv_data;
>> +
>> +    if (!ctx->print_deinit_summary)
>> +        return;
>> +
>> +    printf("flush count: %d\n", ctx->flush_count);
>> +    printf("pts seen nr: %d\n", ctx->pts_written_nr);
>> +    printf("pts seen: ");
>> +    for (i = 0; i < ctx->pts_written_nr; ++i ) {
>> +        printf(i ? ",%d" : "%d", ctx->pts_written[i]);
>> +    }
>> +    printf("\n");
>> +}
>> +
>> +#define OFF(x) offsetof(FifoTestMuxerContext, x)
>> +static const AVOption fifo_test_options[] = {
>> +        {"write_header_ret", "write_header() return value", OFF(write_header_ret),
>> +         AV_OPT_TYPE_INT, {.i64 = 0}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
>> +        {"write_trailer_ret", "write_trailer() return value", OFF(write_trailer_ret),
>> +         AV_OPT_TYPE_INT, {.i64 = 0}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
>> +        {"print_deinit_summary", "print summary when deinitializing muxer", OFF(print_deinit_summary),
>> +         AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM},
>> +        {NULL}
>> +    };
>> +
>> +static const AVClass failing_muxer_class = {
>> +    .class_name = "Fifo test muxer",
>> +    .item_name  = av_default_item_name,
>> +    .option     = fifo_test_options,
>> +    .version    = LIBAVUTIL_VERSION_INT,
>> +};
>> +
>> +const FFOutputFormat ff_fifo_test_muxer = {
>> +    .p.name         = "fifo_test",
>> +    .p.long_name    = NULL_IF_CONFIG_SMALL("Fifo test muxer"),
>> +    .priv_data_size = sizeof(FifoTestMuxerContext),
>> +    .write_header   = failing_write_header,
>> +    .write_packet   = failing_write_packet,
>> +    .write_trailer  = failing_write_trailer,
>> +    .deinit         = failing_deinit,
>> +    .p.priv_class   = &failing_muxer_class,
>> +#if FF_API_ALLOW_FLUSH
>> +    .p.flags        = AVFMT_NOFILE | AVFMT_ALLOW_FLUSH,
>> +#else
>> +    .p.flags        = AVFMT_NOFILE,
>> +#endif
>> +    .flags_internal = FF_FMT_ALLOW_FLUSH,
> 
>> +};
>> +
>> +
> 
> nit++++: drop double empty line

This is actually intentional to separate the test muxer from the actual
test tool.

> 
>>  static int prepare_packet(AVPacket *pkt, const FailingMuxerPacketData *pkt_data, int64_t pts)
>>  {
>>      int ret = av_new_packet(pkt, sizeof(*pkt_data));
>> -- 
>> 2.40.1
> 
> LGTM, thanks.
Stefano Sabatini March 12, 2024, 8:47 p.m. UTC | #3 
On date Tuesday 2024-03-12 21:25:31 +0100, Andreas Rheinhardt wrote:
[...]
> > nit: FifoTestMuxerPacketData
> > 
> 
> This would necessitate changes to the part of the test tool that I did
> not change and would therefore need to be a commit of its own. I can do
> this, of course.

Of course, feel free to ignore the nits and just push, we can followup
later.
diff mbox series

Patch

diff --git a/libavformat/Makefile b/libavformat/Makefile
index 785349c036..94a949f555 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -205,7 +205,6 @@  OBJS-$(CONFIG_EPAF_DEMUXER)              += epafdec.o pcm.o
 OBJS-$(CONFIG_FFMETADATA_DEMUXER)        += ffmetadec.o
 OBJS-$(CONFIG_FFMETADATA_MUXER)          += ffmetaenc.o
 OBJS-$(CONFIG_FIFO_MUXER)                += fifo.o
-OBJS-$(CONFIG_FIFO_TEST_MUXER)           += fifo_test.o
 OBJS-$(CONFIG_FILMSTRIP_DEMUXER)         += filmstripdec.o
 OBJS-$(CONFIG_FILMSTRIP_MUXER)           += filmstripenc.o rawenc.o
 OBJS-$(CONFIG_FITS_DEMUXER)              += fitsdec.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index 5639715104..e15d0fa6d7 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -165,7 +165,6 @@  extern const FFOutputFormat ff_f4v_muxer;
 extern const FFInputFormat  ff_ffmetadata_demuxer;
 extern const FFOutputFormat ff_ffmetadata_muxer;
 extern const FFOutputFormat ff_fifo_muxer;
-extern const FFOutputFormat ff_fifo_test_muxer;
 extern const FFInputFormat  ff_filmstrip_demuxer;
 extern const FFOutputFormat ff_filmstrip_muxer;
 extern const FFInputFormat  ff_fits_demuxer;
diff --git a/libavformat/fifo.c b/libavformat/fifo.c
index a3d41ba0d3..2a2673f4d8 100644
--- a/libavformat/fifo.c
+++ b/libavformat/fifo.c
@@ -528,6 +528,13 @@  static int fifo_init(AVFormatContext *avf)
     atomic_init(&fifo->queue_duration, 0);
     fifo->last_sent_dts = AV_NOPTS_VALUE;
 
+#ifdef FIFO_TEST
+    /* This exists for the fifo_muxer test tool. */
+    if (fifo->format && !strcmp(fifo->format, "fifo_test")) {
+        extern const FFOutputFormat ff_fifo_test_muxer;
+        oformat = &ff_fifo_test_muxer.p;
+    } else
+#endif
     oformat = av_guess_format(fifo->format, avf->url, NULL);
     if (!oformat) {
         ret = AVERROR_MUXER_NOT_FOUND;
diff --git a/libavformat/fifo_test.c b/libavformat/fifo_test.c
deleted file mode 100644
index 3861c4aee4..0000000000
--- a/libavformat/fifo_test.c
+++ /dev/null
@@ -1,157 +0,0 @@ 
-/*
- * FIFO test pseudo-muxer
- * Copyright (c) 2016 Jan Sebechlebsky
- *
- * This file is part of FFmpeg.
- *
- * FFmpeg is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public License
- * as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * FFmpeg is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public License
- * along with FFmpeg; if not, write to the Free Software * Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#include <stdlib.h>
-
-#include "libavutil/opt.h"
-#include "libavutil/time.h"
-
-#include "avformat.h"
-#include "mux.h"
-#include "url.h"
-
-/* Implementation of mock muxer to simulate real muxer failures */
-
-#define MAX_TST_PACKETS 128
-#define SLEEPTIME_50_MS 50000
-#define SLEEPTIME_10_MS 10000
-
-/* Implementation of mock muxer to simulate real muxer failures */
-
-/* This is structure of data sent in packets to
- * failing muxer */
-typedef struct FailingMuxerPacketData {
-    int ret;             /* return value of write_packet call*/
-    int recover_after;   /* set ret to zero after this number of recovery attempts */
-    unsigned sleep_time; /* sleep for this long in write_packet to simulate long I/O operation */
-} FailingMuxerPacketData;
-
-
-typedef struct FailingMuxerContext {
-    AVClass *class;
-    int write_header_ret;
-    int write_trailer_ret;
-    /* If non-zero, summary of processed packets will be printed in deinit */
-    int print_deinit_summary;
-
-    int flush_count;
-    int pts_written[MAX_TST_PACKETS];
-    int pts_written_nr;
-} FailingMuxerContext;
-
-static int failing_write_header(AVFormatContext *avf)
-{
-    FailingMuxerContext *ctx = avf->priv_data;
-    return ctx->write_header_ret;
-}
-
-static int failing_write_packet(AVFormatContext *avf, AVPacket *pkt)
-{
-    FailingMuxerContext *ctx = avf->priv_data;
-    int ret = 0;
-    if (!pkt) {
-        ctx->flush_count++;
-    } else {
-        FailingMuxerPacketData *data = (FailingMuxerPacketData*) pkt->data;
-
-        if (!data->recover_after) {
-            data->ret = 0;
-        } else {
-            data->recover_after--;
-        }
-
-        ret = data->ret;
-
-        if (data->sleep_time) {
-            int64_t slept = 0;
-            while (slept < data->sleep_time) {
-                if (ff_check_interrupt(&avf->interrupt_callback))
-                    return AVERROR_EXIT;
-                av_usleep(SLEEPTIME_10_MS);
-                slept += SLEEPTIME_10_MS;
-            }
-        }
-
-        if (!ret) {
-            ctx->pts_written[ctx->pts_written_nr++] = pkt->pts;
-            av_packet_unref(pkt);
-        }
-    }
-    return ret;
-}
-
-static int failing_write_trailer(AVFormatContext *avf)
-{
-    FailingMuxerContext *ctx = avf->priv_data;
-    return ctx->write_trailer_ret;
-}
-
-static void failing_deinit(AVFormatContext *avf)
-{
-    int i;
-    FailingMuxerContext *ctx = avf->priv_data;
-
-    if (!ctx->print_deinit_summary)
-        return;
-
-    printf("flush count: %d\n", ctx->flush_count);
-    printf("pts seen nr: %d\n", ctx->pts_written_nr);
-    printf("pts seen: ");
-    for (i = 0; i < ctx->pts_written_nr; ++i ) {
-        printf(i ? ",%d" : "%d", ctx->pts_written[i]);
-    }
-    printf("\n");
-}
-#define OFFSET(x) offsetof(FailingMuxerContext, x)
-static const AVOption options[] = {
-        {"write_header_ret", "write_header() return value", OFFSET(write_header_ret),
-         AV_OPT_TYPE_INT, {.i64 = 0}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
-        {"write_trailer_ret", "write_trailer() return value", OFFSET(write_trailer_ret),
-         AV_OPT_TYPE_INT, {.i64 = 0}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
-        {"print_deinit_summary", "print summary when deinitializing muxer", OFFSET(print_deinit_summary),
-         AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM},
-        {NULL}
-    };
-
-static const AVClass failing_muxer_class = {
-    .class_name = "Fifo test muxer",
-    .item_name  = av_default_item_name,
-    .option     = options,
-    .version    = LIBAVUTIL_VERSION_INT,
-};
-
-const FFOutputFormat ff_fifo_test_muxer = {
-    .p.name         = "fifo_test",
-    .p.long_name    = NULL_IF_CONFIG_SMALL("Fifo test muxer"),
-    .priv_data_size = sizeof(FailingMuxerContext),
-    .write_header   = failing_write_header,
-    .write_packet   = failing_write_packet,
-    .write_trailer  = failing_write_trailer,
-    .deinit         = failing_deinit,
-    .p.priv_class   = &failing_muxer_class,
-#if FF_API_ALLOW_FLUSH
-    .p.flags        = AVFMT_NOFILE | AVFMT_ALLOW_FLUSH,
-#else
-    .p.flags        = AVFMT_NOFILE,
-#endif
-    .flags_internal = FF_FMT_ALLOW_FLUSH,
-};
-
diff --git a/libavformat/tests/fifo_muxer.c b/libavformat/tests/fifo_muxer.c
index 11a557c1a0..34aaa55326 100644
--- a/libavformat/tests/fifo_muxer.c
+++ b/libavformat/tests/fifo_muxer.c
@@ -23,8 +23,20 @@ 
 #include "libavutil/opt.h"
 #include "libavutil/time.h"
 #include "libavformat/avformat.h"
+#include "libavformat/mux.h"
 #include "libavformat/url.h"
-#include "libavformat/network.h"
+
+/*
+ * Include fifo.c directly to override libavformat/fifo.c and
+ * thereby prevent libavformat/fifo.o from being pulled in when linking.
+ * This relies on libavformat always being linked statically to its
+ * test tools (like this one).
+ * Due to FIFO_TEST, our fifo muxer will include special handling
+ * for tests, i.e. it allows to select the fifo_test muxer below
+ * even though it is not accessible via the API.
+ */
+#define FIFO_TEST
+#include "libavformat/fifo.c"
 
 #define MAX_TST_PACKETS 128
 #define SLEEPTIME_50_MS 50000
@@ -38,6 +50,118 @@  typedef struct FailingMuxerPacketData {
     unsigned sleep_time; /* sleep for this long in write_packet to simulate long I/O operation */
 } FailingMuxerPacketData;
 
+typedef struct FifoTestMuxerContext {
+    AVClass *class;
+    int write_header_ret;
+    int write_trailer_ret;
+    /* If non-zero, summary of processed packets will be printed in deinit */
+    int print_deinit_summary;
+
+    int flush_count;
+    int pts_written[MAX_TST_PACKETS];
+    int pts_written_nr;
+} FifoTestMuxerContext;
+
+static int failing_write_header(AVFormatContext *avf)
+{
+    FifoTestMuxerContext *ctx = avf->priv_data;
+    return ctx->write_header_ret;
+}
+
+static int failing_write_packet(AVFormatContext *avf, AVPacket *pkt)
+{
+    FifoTestMuxerContext *ctx = avf->priv_data;
+    int ret = 0;
+    if (!pkt) {
+        ctx->flush_count++;
+    } else {
+        FailingMuxerPacketData *data = (FailingMuxerPacketData*) pkt->data;
+
+        if (!data->recover_after) {
+            data->ret = 0;
+        } else {
+            data->recover_after--;
+        }
+
+        ret = data->ret;
+
+        if (data->sleep_time) {
+            int64_t slept = 0;
+            while (slept < data->sleep_time) {
+                if (ff_check_interrupt(&avf->interrupt_callback))
+                    return AVERROR_EXIT;
+                av_usleep(SLEEPTIME_10_MS);
+                slept += SLEEPTIME_10_MS;
+            }
+        }
+
+        if (!ret) {
+            ctx->pts_written[ctx->pts_written_nr++] = pkt->pts;
+            av_packet_unref(pkt);
+        }
+    }
+    return ret;
+}
+
+static int failing_write_trailer(AVFormatContext *avf)
+{
+    FifoTestMuxerContext *ctx = avf->priv_data;
+    return ctx->write_trailer_ret;
+}
+
+static void failing_deinit(AVFormatContext *avf)
+{
+    int i;
+    FifoTestMuxerContext *ctx = avf->priv_data;
+
+    if (!ctx->print_deinit_summary)
+        return;
+
+    printf("flush count: %d\n", ctx->flush_count);
+    printf("pts seen nr: %d\n", ctx->pts_written_nr);
+    printf("pts seen: ");
+    for (i = 0; i < ctx->pts_written_nr; ++i ) {
+        printf(i ? ",%d" : "%d", ctx->pts_written[i]);
+    }
+    printf("\n");
+}
+
+#define OFF(x) offsetof(FifoTestMuxerContext, x)
+static const AVOption fifo_test_options[] = {
+        {"write_header_ret", "write_header() return value", OFF(write_header_ret),
+         AV_OPT_TYPE_INT, {.i64 = 0}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
+        {"write_trailer_ret", "write_trailer() return value", OFF(write_trailer_ret),
+         AV_OPT_TYPE_INT, {.i64 = 0}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
+        {"print_deinit_summary", "print summary when deinitializing muxer", OFF(print_deinit_summary),
+         AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM},
+        {NULL}
+    };
+
+static const AVClass failing_muxer_class = {
+    .class_name = "Fifo test muxer",
+    .item_name  = av_default_item_name,
+    .option     = fifo_test_options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
+const FFOutputFormat ff_fifo_test_muxer = {
+    .p.name         = "fifo_test",
+    .p.long_name    = NULL_IF_CONFIG_SMALL("Fifo test muxer"),
+    .priv_data_size = sizeof(FifoTestMuxerContext),
+    .write_header   = failing_write_header,
+    .write_packet   = failing_write_packet,
+    .write_trailer  = failing_write_trailer,
+    .deinit         = failing_deinit,
+    .p.priv_class   = &failing_muxer_class,
+#if FF_API_ALLOW_FLUSH
+    .p.flags        = AVFMT_NOFILE | AVFMT_ALLOW_FLUSH,
+#else
+    .p.flags        = AVFMT_NOFILE,
+#endif
+    .flags_internal = FF_FMT_ALLOW_FLUSH,
+};
+
+
 static int prepare_packet(AVPacket *pkt, const FailingMuxerPacketData *pkt_data, int64_t pts)
 {
     int ret = av_new_packet(pkt, sizeof(*pkt_data));