From bef4930a2bf280425b5952de0e2281f03897ff7c 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>
---
configure | 3 +
doc/demuxers.texi | 18 +++
doc/ffprobe-format.texi | 121 ++++++++++++++
doc/formats.texi | 1 +
libavformat/Makefile | 1 +
libavformat/allformats.c | 1 +
libavformat/ffprobedec.c | 405 +++++++++++++++++++++++++++++++++++++++++++++++
7 files changed, 550 insertions(+)
create mode 100644 doc/ffprobe-format.texi
create mode 100644 libavformat/ffprobedec.c
@@ -3340,6 +3340,9 @@ for n in $COMPONENT_LIST; do
eval ${n}_if_any="\$$v"
done
+# Disable ffprobe demuxer for security concerns
+disable ffprobe_demuxer
+
enable $ARCH_EXT_LIST
die_unknown(){
@@ -243,6 +243,24 @@ file subdir/file-2.wav
@end example
@end itemize
+@section ffprobe
+
+ffprobe internal demuxer. It is able to demux files in the format
+specified in the @ref{FFprobe demuxer format} chapter.
+
+For security reasons this demuxer is disabled by default, should be
+enabled though the @code{--enable-demuxer=ffprobe} configure option.
+
+This format is useful to generate streams in a textual format, easily
+generated with scripting or by hand (by editing the output of
+@command{ffprobe}).
+
+In particular, it can be also used to inject data stream generated by
+scripts in the @command{ffmpeg} output, for example with the command:
+@example
+ffmpeg -i INPUT -i data.ffprobe -map 0:0 -map 0:1 -map 1:0 -codec:d copy OUTPUT
+@end example
+
@section flv
Adobe Flash Video Format demuxer.
new file mode 100644
@@ -0,0 +1,121 @@
+@anchor{FFprobe demuxer format}
+@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 (@samp{FORMAT}, @samp{STREAM},
+@samp{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
+@samp{key=value}. In the case of data the key and the value must
+stay on different lines.
+
+Unrecognized values are discarded.
+
+This format can be read by the @code{ffprobe} demuxer. It is an
+internal format and thus should not be used for archiving purposes.
+
+The following sections document the fields accepted by each section.
+
+@section FORMAT
+
+@table @samp
+@item nb_streams
+the number of supported streams
+@end table
+
+@section STREAM
+@table @samp
+@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 @samp
+@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_time
+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.
+
+Each line should not be longer than 4095 bytes.
+@end table
+
+@section Examples
+
+A ffprobe demuxer file might look like this:
+@example
+[FORMAT]
+nb_streams=1
+format_name=ffprobe
+[/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
+
+@c man end FFPROBE DEMUXER FORMAT
@@ -251,3 +251,4 @@ The exact semantics of stream specifiers is defined by the
@include muxers.texi
@end ifclear
@include metadata.texi
+@include ffprobe-format.texi
@@ -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_DEMUXER) += ffprobedec.o
OBJS-$(CONFIG_FIFO_MUXER) += fifo.o
OBJS-$(CONFIG_FILMSTRIP_DEMUXER) += filmstripdec.o
OBJS-$(CONFIG_FILMSTRIP_MUXER) += filmstripenc.o
@@ -123,6 +123,7 @@ void av_register_all(void)
REGISTER_MUXER (F4V, f4v);
REGISTER_MUXDEMUX(FFM, ffm);
REGISTER_MUXDEMUX(FFMETADATA, ffmetadata);
+ REGISTER_DEMUXER (FFPROBE, ffprobe);
REGISTER_MUXER (FIFO, fifo);
REGISTER_MUXDEMUX(FILMSTRIP, filmstrip);
REGISTER_MUXDEMUX(FLAC, flac);
new file mode 100644
@@ -0,0 +1,405 @@
+/*
+ * 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;
+
+#define LINE_BUFFER_SIZE 4096
+
+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[LINE_BUFFER_SIZE];
+ 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, readlen;
+ size_t l;
+
+ if ((ret = ff_get_line2(avf->pb, buf, size, &readlen)) <= 0)
+ return ret;
+ if (readlen > ret) {
+ av_log(avf, AV_LOG_ERROR,
+ "Input read line was %d bytes long, maximum supported length is %zu\n",
+ readlen, size-1);
+ return AVERROR(EINVAL);
+ }
+ 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[LINE_BUFFER_SIZE], *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_class = {
+ .class_name = "ffprobe demuxer",
+ .item_name = av_default_item_name,
+ .version = LIBAVUTIL_VERSION_INT,
+};
+
+AVInputFormat ff_ffprobe_demuxer = {
+ .name = "ffprobe",
+ .long_name = NULL_IF_CONFIG_SMALL("FFprobe alike output"),
+ .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_class,
+};
--
1.9.1