[FFmpeg-devel] lavf: add ffprobe demuxer

Message ID	20160917162559.GL10784@barisone
State	Superseded
Headers	show Delivered-To: ffmpegpatchwork@gmail.com Received-SPF: pass (google.com: domain of ffmpeg-devel-bounces@ffmpeg.org designates 79.124.17.100 as permitted sender) client-ip=79.124.17.100; Date: Sat, 17 Sep 2016 18:25:59 +0200 From: Stefano Sabatini <stefasab@gmail.com> To: FFmpeg development discussions and patches <ffmpeg-devel@ffmpeg.org> Message-ID: <20160917162559.GL10784@barisone> Mail-Followup-To: FFmpeg development discussions and patches <ffmpeg-devel@ffmpeg.org> References: <1473006277-16196-1-git-send-email-stefasab@gmail.com> <20160904212556.GW4692@nb4> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="s/l3CgOIzMHHjg/5" Content-Disposition: inline In-Reply-To: <20160904212556.GW4692@nb4> User-Agent: Mutt/1.5.21 (2010-09-15) Subject: Re: [FFmpeg-devel] [PATCH] lavf: add ffprobe demuxer Precedence: list Reply-To: FFmpeg development discussions and patches <ffmpeg-devel@ffmpeg.org> Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" <ffmpeg-devel-bounces@ffmpeg.org>

From bd026e67a4876cff4e50edfb7f0958c87eacbef0 Mon Sep 17 00:00:00 2001 From: Nicolas George <george@nsup.org> Date: Sat, 11 Jan 2014 19:42:41 +0100 Subject: [PATCH] lavf: add ffprobe demuxer With several modifications and documentation by Stefano Sabatini <stefasab@gmail.com>. Signed-off-by: Nicolas George <george@nsup.org> --- doc/ffprobe-format.texi | 130 ++++++++++++++++ libavformat/Makefile | 1 + libavformat/allformats.c | 1 + libavformat/ffprobedec.c | 397 +++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 529 insertions(+) create mode 100644 doc/ffprobe-format.texi create mode 100644 libavformat/ffprobedec.c diff --git a/doc/ffprobe-format.texi b/doc/ffprobe-format.texi new file mode 100644 index 0000000..be7af15 --- /dev/null +++ b/doc/ffprobe-format.texi @@ -0,0 +1,130 @@ +@chapter ffprobe demuxer format +@c man begin FFPROBE DEMUXER FORMAT + +The ffprobe demuxer format is inspired by the output generated by the +ffprobe default format. + +It consists of several sections (FORMAT, STREAM, PACKET). Each section +starts with a single line in the format @samp{[SECTION]} and ends with +the corresponding line @samp{[/SECTION]}. + +where @samp{SECTION} is the name of the section. + +A well-formed file consists of an initial @samp{FORMAT} section, +followed by several @samp{STREAM} sections (one per stream), and +several @samp{PACKET} sections. + +Each section contains a sequence of lines in the form +@sample{key=value}. In the case of data the key and the value must +stay on different lines. + +Unrecognized values are discarded (this allows the demuxer to accept +the output generated by @program{ffprobe} without further +modifications. + +The following sections document the fields accepted by each section. + +@section FORMAT + +@table +@item nb_streams +the number of supported streams +@end table + +@section STREAM +@table +@item index +the index number +@item codec_name +the codec name (the name must be an accepted FFmpeg codec name +@item time_base +Specify the time_base as @samp{NUM/DEN}, this is the time base used to +specify the timestamps in the corresponding packets +@end table + +@section PACKET + +@table +@item stream_index +the stream index of the stream (must have been specified in a stream +section). If not specified the first stream is assumed. + +@item pts +the PTS expressed in the corresponding time base stream units + +@item pts_time +the PTS expressed as an absolute time, using the FFmpeg time syntax + +@item dts +the DTS expressed in the corresponding time base stream units + +@item pts_time +the DTS expressed as an absolute time, using the FFmpeg time syntax + +@item duration +the duration expressed in the corresponding time base stream units + +@item duration_tim +the packet duration expressed as an absolute time, using the FFmpeg time syntax + +@item flags +If the value is equal to "K" mark the packet as a key packet + +@item data +specifies the data as a sequence of hexadecimal values (two +hexadecimal values specify a byte). The data specification starts on +the following line and can span over several lines, and must be +terminated by an empty line. Spaces within each line are discarded. +@end table + +@section Examples + +A ffprobe demuxer file might look like this: +@example +[FORMAT] +nb_streams=1 +format_name=ffprobe_default +[/FORMAT] +[STREAM] +index=0 +codec_name=timed_id3 +time_base=1/1000000 +[/STREAM] +[PACKET] +stream_index=0 +pts_time=0 +dts_time=0 +duration=N/A +flags=K +data= +f000 0000 0167 42c0 1ed9 81b1 fefc 0440 +57ff d7d1 dfff e11a 3d7e 6cbd 0000 0001 +ce8c 4d9d 108e 25e9 fe + +[/PACKET] +[PACKET] +stream_index=0 +pts_time=1.00 +duration=N/A +flags=K +data= +f000 0000 0141 9a38 3be5 ffff ffff fffa +ebc1 3782 7d5e 21e9 ffff abf2 ea4f ed66 +0000 0001 ce8c 4d9d 108e 25e9 fe + +[/PACKET] +@end example + +The output generated by the @program{ffprobe} default format is valid +if the following options are also specified: +@example +-show_packets -show_data -show_compact_data -show_format -show_streams -show_packets -show_headers_first +@end example + +Thus, to generate the corresponding output from an input file you can +do: +@example +ffprobe INPUT.ts -show_packets -show_data -show_compact_data -show_format -show_streams -show_packets -show_headers_first > OUTPUT.ffprobe +@end example + +@c man end FFPROBE DEMUXER FORMAT diff --git a/libavformat/Makefile b/libavformat/Makefile index 5d827d31..04467be 100644 --- a/libavformat/Makefile +++ b/libavformat/Makefile @@ -162,6 +162,7 @@ OBJS-$(CONFIG_FFM_DEMUXER) += ffmdec.o OBJS-$(CONFIG_FFM_MUXER) += ffmenc.o OBJS-$(CONFIG_FFMETADATA_DEMUXER) += ffmetadec.o OBJS-$(CONFIG_FFMETADATA_MUXER) += ffmetaenc.o +OBJS-$(CONFIG_FFPROBE_DEFAULT_DEMUXER) += ffprobedec.o OBJS-$(CONFIG_FIFO_MUXER) += fifo.o OBJS-$(CONFIG_FILMSTRIP_DEMUXER) += filmstripdec.o OBJS-$(CONFIG_FILMSTRIP_MUXER) += filmstripenc.o diff --git a/libavformat/allformats.c b/libavformat/allformats.c index 6a216ef..8ef1822 100644 --- a/libavformat/allformats.c +++ b/libavformat/allformats.c @@ -123,6 +123,7 @@ void av_register_all(void) REGISTER_MUXER (F4V, f4v); REGISTER_MUXDEMUX(FFM, ffm); REGISTER_MUXDEMUX(FFMETADATA, ffmetadata); + REGISTER_DEMUXER (FFPROBE_DEFAULT, ffprobe_default); REGISTER_MUXER (FIFO, fifo); REGISTER_MUXDEMUX(FILMSTRIP, filmstrip); REGISTER_MUXDEMUX(FLAC, flac); diff --git a/libavformat/ffprobedec.c b/libavformat/ffprobedec.c new file mode 100644 index 0000000..3a631c9 --- /dev/null +++ b/libavformat/ffprobedec.c @@ -0,0 +1,397 @@ +/* + * Copyright (c) 2013 Nicolas George + * + * 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 "libavutil/avassert.h" +#include "libavutil/avstring.h" +#include "libavutil/bprint.h" +#include "libavutil/parseutils.h" +#include "avformat.h" +#include "internal.h" + +enum SectionType { + SEC_NONE = 0, + SEC_FORMAT, + SEC_STREAM, + SEC_PACKET, +}; + +const char *const section_names[] = { + [SEC_NONE] = "NONE", + [SEC_FORMAT] = "FORMAT", + [SEC_STREAM] = "STREAM", + [SEC_PACKET] = "PACKET", +}; + +typedef struct { + AVClass *class; + enum SectionType section; + AVBPrint data; + int packet_nb; +} FFprobeContext; + +static int ffprobe_probe(AVProbeData *probe) +{ + unsigned score; + + if (!av_strstart(probe->buf, "[FORMAT]\n", NULL)) + return 0; + score = !!strstr(probe->buf, "\nnb_streams=") + + !!strstr(probe->buf, "\nnb_programs=") + + !!strstr(probe->buf, "\nformat_name=") + + !!strstr(probe->buf, "\nstart_time=") + + !!strstr(probe->buf, "\nsize="); + return score >= 3 ? AVPROBE_SCORE_MAX : AVPROBE_SCORE_MAX / 2; +} + +static int ffprobe_read_close(AVFormatContext *avf) +{ + FFprobeContext *ffp = avf->priv_data; + + av_bprint_finalize(&ffp->data, NULL); + return 0; +} + +/** + * Read a section start line ("[SECTION]"). + * Update FFprobeContext.section. + * @return SectionType (>0) for success, + * SEC_NONE if no section start, + * <0 for error + */ +static int read_section_start(AVFormatContext *avf) +{ + FFprobeContext *ffp = avf->priv_data; + uint8_t buf[4096]; + const char *rest; + int i, ret; + + ret = ff_get_line(avf->pb, buf, sizeof(buf)); + if (ret == 0 && avio_feof(avf->pb)) + ret = AVERROR_EOF; + if (ret <= 0) + return ret; + if (*buf != '[') + return 0; + for (i = 1; i < FF_ARRAY_ELEMS(section_names); i++) { + if (av_strstart(buf + 1, section_names[i], &rest) && + !strcmp(rest, "]\n")) { + ffp->section = i; + return i; + } + } + return SEC_NONE; +} + +/** + * Read a line from within a section. + * @return >0 for success, 0 if end of section, <0 for error + */ +static int read_section_line(AVFormatContext *avf, uint8_t *buf, size_t size) +{ + FFprobeContext *ffp = avf->priv_data; + const char *rest; + int ret; + size_t l; + + if ((ret = ff_get_line(avf->pb, buf, size)) <= 0) + return ret; + if (av_strstart(buf, "[/", &rest)) { + ffp->section = 0; + return 0; + } + if ((l = strlen(buf)) > 0 && buf[l - 1] == '\n') + buf[--l] = 0; + return 1; +} + +/** + * Read hexadecimal data + * Store it in FFprobeContext.data. + * @return >=0 for success, <0 for error + */ +static int read_data(AVFormatContext *avf, int *size) +{ + FFprobeContext *ffp = avf->priv_data; + uint8_t buf[4096], *cur; + int ret, pos, val; + + if (ffp->data.len) + return AVERROR_INVALIDDATA; + while ((ret = read_section_line(avf, buf, sizeof(buf)))) { + if (ret < 0) + return ret; + if (!buf[0]) + break; + cur = buf; + pos = 0; + cur += pos; + while (1) { + while (*cur == ' ') + cur++; + if (!*cur) + break; + if ((unsigned)(*cur - '0') >= 10 && + (unsigned)(*cur - 'a') >= 6 && + (unsigned)(*cur - 'A') >= 6) { + av_log(avf, AV_LOG_ERROR, + "Invalid character %c in packet number %d data\n", *cur, ffp->packet_nb); + return AVERROR_INVALIDDATA; + } + pos = 0; + if (sscanf(cur, " %02x%n", &val, &pos) < 1 || !pos) { + av_log(avf, AV_LOG_ERROR, + "Could not parse value in packet number %d data\n", ffp->packet_nb); + return AVERROR_INVALIDDATA; + } + cur += pos; + av_bprint_chars(&ffp->data, val, 1); + } + } + + if (size) + *size = ffp->data.len; + + return av_bprint_is_complete(&ffp->data) ? 0 : AVERROR(ENOMEM); +} + +static int read_section_format(AVFormatContext *avf) +{ + uint8_t buf[4096]; + int ret, val; + + while ((ret = read_section_line(avf, buf, sizeof(buf)))) { + if (ret < 0) + return ret; + if (sscanf(buf, "nb_streams=%d", &val) >= 1) { + while (avf->nb_streams < val) + if (!avformat_new_stream(avf, NULL)) + return AVERROR(ENOMEM); + } + /* TODO programs */ + /* TODO start_time duration bit_rate */ + /* TODO tags */ + } + return SEC_FORMAT; +} + +static int read_section_stream(AVFormatContext *avf) +{ + FFprobeContext *ffp = avf->priv_data; + uint8_t buf[4096]; + int ret, index, val1, val2; + AVStream *st = NULL; + const char *val; + + av_bprint_clear(&ffp->data); + while ((ret = read_section_line(avf, buf, sizeof(buf)))) { + if (ret < 0) + return ret; + if (!st) { + if (sscanf(buf, "index=%d", &index) >= 1) { + if (index == avf->nb_streams) { + if (!avformat_new_stream(avf, NULL)) + return AVERROR(ENOMEM); + } + if ((unsigned)index >= avf->nb_streams) { + av_log(avf, AV_LOG_ERROR, "Invalid stream index: %d\n", + index); + return AVERROR_INVALIDDATA; + } + st = avf->streams[index]; + } else { + av_log(avf, AV_LOG_ERROR, "Stream without index\n"); + return AVERROR_INVALIDDATA; + } + } + if (av_strstart(buf, "codec_name=", &val)) { + const AVCodecDescriptor *desc = avcodec_descriptor_get_by_name(val); + if (desc) { + st->codecpar->codec_id = desc->id; + st->codecpar->codec_type = desc->type; + } + if (!desc) { + av_log(avf, AV_LOG_WARNING, "Cannot recognize codec name '%s'", val); + } + } else if (!strcmp(buf, "extradata=")) { + if ((ret = read_data(avf, NULL)) < 0) + return ret; + if (ffp->data.len) { + if ((ret = ff_alloc_extradata(st->codecpar, ffp->data.len)) < 0) + return ret; + memcpy(st->codecpar->extradata, ffp->data.str, ffp->data.len); + } + } else if (sscanf(buf, "time_base=%d/%d", &val1, &val2) >= 2) { + st->time_base.num = val1; + st->time_base.den = val2; + } + } + return SEC_STREAM; +} + +static int read_section_packet(AVFormatContext *avf, AVPacket *pkt) +{ + FFprobeContext *ffp = avf->priv_data; + uint8_t buf[4096]; + int ret; + AVPacket p; + char flags; + + av_init_packet(&p); + p.pos = avio_tell(avf->pb); + p.stream_index = -1; + p.size = -1; + av_bprint_clear(&ffp->data); + while ((ret = read_section_line(avf, buf, sizeof(buf)))) { + int has_time = 0; + int64_t pts, dts, duration; + char timebuf[1024]; + + if (ret < 0) + return ret; + if (sscanf(buf, "stream_index=%d", &p.stream_index)) { + if ((unsigned)p.stream_index >= avf->nb_streams) { + av_log(avf, AV_LOG_ERROR, "Invalid stream number %d specified in packet number %d\n", + p.stream_index, ffp->packet_nb); + return AVERROR_INVALIDDATA; + } + } + +#define PARSE_TIME(name_, is_duration) \ + sscanf(buf, #name_ "=%"SCNi64, &p.name_); \ + has_time = sscanf(buf, #name_ "_time=%s", timebuf); \ + if (has_time) { \ + int stream_index = p.stream_index == -1 ? 0 : p.stream_index; \ + \ + if (!strcmp(timebuf, "N/A")) { \ + p.name_ = is_duration ? 0 : AV_NOPTS_VALUE; \ + } else { \ + ret = av_parse_time(&name_, timebuf, 1); \ + if (ret < 0) { \ + av_log(avf, AV_LOG_ERROR, "Invalid " #name_ " time specification '%s' for data packet\n", \ + timebuf); \ + return ret; \ + } \ + p.name_ = av_rescale_q(name_, AV_TIME_BASE_Q, avf->streams[stream_index]->time_base); \ + } \ + } \ + + PARSE_TIME(pts, 0); + PARSE_TIME(dts, 0); + PARSE_TIME(duration, 1); + + if (sscanf(buf, "flags=%c", &flags) >= 1) + p.flags = flags == 'K' ? AV_PKT_FLAG_KEY : 0; + if (!strcmp(buf, "data=")) + if ((ret = read_data(avf, &p.size)) < 0) + return ret; + } + if (p.size < 0 || (unsigned)p.stream_index >= avf->nb_streams) + return SEC_NONE; + if ((ret = av_new_packet(pkt, p.size)) < 0) + return ret; + p.data = pkt->data; + p.buf = pkt->buf; + *pkt = p; + if (ffp->data.len) { + ffp->data.len = FFMIN(ffp->data.len, pkt->size); + memcpy(pkt->data, ffp->data.str, ffp->data.len); + } + return SEC_PACKET; +} + +static int read_section(AVFormatContext *avf, AVPacket *pkt) +{ + FFprobeContext *ffp = avf->priv_data; + int ret, section; + + while (!ffp->section) + if ((ret = read_section_start(avf)) < 0) + return ret; + switch (section = ffp->section) { + case SEC_FORMAT: + return read_section_format(avf); + case SEC_STREAM: + return read_section_stream(avf); + case SEC_PACKET: + ret = read_section_packet(avf, pkt); + ffp->packet_nb++; + return ret; + default: + av_assert0(!"reached"); + return AVERROR_BUG; + } +} + +static int ffprobe_read_header(AVFormatContext *avf) +{ + FFprobeContext *ffp = avf->priv_data; + int ret; + + av_bprint_init(&ffp->data, 0, AV_BPRINT_SIZE_UNLIMITED); + if ((ret = read_section_start(avf)) < 0) + return ret; + if (ret != SEC_FORMAT) { + av_log(avf, AV_LOG_INFO, "Using noheader mode\n"); + avf->ctx_flags |= AVFMTCTX_NOHEADER; + return 0; + } + if ((ret = read_section_format(avf)) < 0) + return ret; + + /* read stream information */ + while (1) { + ret = read_section_start(avf); + if (ret != SEC_STREAM) + break; + if ((ret = read_section_stream(avf)) < 0) + return ret; + } + + return 0; +} + +static int ffprobe_read_packet(AVFormatContext *avf, AVPacket *pkt) +{ + int ret; + + while (1) { + if ((ret = read_section(avf, pkt)) < 0) + return ret; + if (ret == SEC_PACKET) + return 0; + } +} + +static const AVClass ffprobe_default_class = { + .class_name = "ffprobe_default demuxer", + .item_name = av_default_item_name, + .version = LIBAVUTIL_VERSION_INT, +}; + +AVInputFormat ff_ffprobe_default_demuxer = { + .name = "ffprobe_default", + .long_name = NULL_IF_CONFIG_SMALL("FFprobe output (default writer)"), + .priv_data_size = sizeof(FFprobeContext), + .read_probe = ffprobe_probe, + .read_header = ffprobe_read_header, + .read_packet = ffprobe_read_packet, + .read_close = ffprobe_read_close, + .priv_class = &ffprobe_default_class, +}; -- 1.9.1

[FFmpeg-devel] lavf: add ffprobe demuxer

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