* [FFmpeg-devel] [PATCH v2 1/2] avformat/mvdec: make audio stream conditional
2022-01-01 1:11 [FFmpeg-devel] [PATCH v2 0/2] avformat/mvdec: make audio stream conditional John-Paul Stewart
@ 2022-01-01 1:11 ` John-Paul Stewart
2022-01-01 1:11 ` [FFmpeg-devel] [PATCH v2 2/2] avformat/mvdec: re-indent after last commit John-Paul Stewart
2022-01-05 6:18 ` [FFmpeg-devel] [PATCH v2 0/2] avformat/mvdec: make audio stream conditional Peter Ross
2 siblings, 0 replies; 4+ messages in thread
From: John-Paul Stewart @ 2022-01-01 1:11 UTC (permalink / raw)
To: ffmpeg-devel
Only allocate an audio stream if there is one in the data. Silicon
Graphics movie format will contain default values (16 bit samples, 2
audio channels, 22050 Hz sample rate) even when no audio is present in
the file. This confuses FFmpeg into thinking such an audio stream is
present with 0 samples in it.
There is a flag value in the format to indicate whether or not audio is
present. This patch checks that and behaves accordingly.
Signed-off-by: John-Paul Stewart <jpstewart@personalprojects.net>
---
libavformat/mvdec.c | 22 +++++++++++++++++++---
1 file changed, 19 insertions(+), 3 deletions(-)
diff --git a/libavformat/mvdec.c b/libavformat/mvdec.c
index ea955d2b11..0f0474141b 100644
--- a/libavformat/mvdec.c
+++ b/libavformat/mvdec.c
@@ -45,6 +45,10 @@ typedef struct MvContext {
int aformat; ///< audio format
} MvContext;
+/* these magic numbers are defined in moviefile.h on Silicon Grahpics IRIX */
+#define MOVIE_SOUND 1
+#define MOVIE_SILENT 2
+
#define AUDIO_FORMAT_SIGNED 401
static int mv_probe(const AVProbeData *p)
@@ -305,18 +309,25 @@ static int mv_read_header(AVFormatContext *avctx)
avio_skip(pb, 10);
+ fps = av_d2q(av_int2double(avio_rb64(pb)), INT_MAX);
+
/* allocate audio track first to prevent unnecessary seeking
* (audio packet always precede video packet for a given frame) */
+ v = avio_rb16(pb);
+ if (v == MOVIE_SOUND) {
+ /* movie has sound so allocate an audio stream */
ast = avformat_new_stream(avctx, NULL);
if (!ast)
return AVERROR(ENOMEM);
+ } else if (v != MOVIE_SILENT)
+ return AVERROR_INVALIDDATA;
+
+ avio_skip(pb, 2);
vst = avformat_new_stream(avctx, NULL);
if (!vst)
return AVERROR(ENOMEM);
- fps = av_d2q(av_int2double(avio_rb64(pb)), INT_MAX);
avpriv_set_pts_info(vst, 64, fps.den, fps.num);
- avio_skip(pb, 4);
vst->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
vst->avg_frame_rate = fps;
vst->duration = vst->nb_frames = avio_rb32(pb);
@@ -338,6 +349,7 @@ static int mv_read_header(AVFormatContext *avctx)
vst->codecpar->height = avio_rb32(pb);
avio_skip(pb, 12);
+ if (ast) {
ast->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
ast->nb_frames = vst->nb_frames;
ast->codecpar->sample_rate = avio_rb32(pb);
@@ -373,6 +385,8 @@ static int mv_read_header(AVFormatContext *avctx)
return AVERROR_INVALIDDATA;
avio_skip(pb, 8);
+ } else
+ avio_skip(pb, 24); /* skip meaningless audio metadata */
var_read_metadata(avctx, "title", 0x80);
var_read_metadata(avctx, "comment", 0x100);
@@ -386,9 +400,11 @@ static int mv_read_header(AVFormatContext *avctx)
if (avio_feof(pb))
return AVERROR_INVALIDDATA;
avio_skip(pb, 8);
+ if (ast) {
av_add_index_entry(ast, pos, timestamp, asize, 0, AVINDEX_KEYFRAME);
- av_add_index_entry(vst, pos + asize, i, vsize, 0, AVINDEX_KEYFRAME);
timestamp += asize / (ast->codecpar->channels * (uint64_t)bytes_per_sample);
+ }
+ av_add_index_entry(vst, pos + asize, i, vsize, 0, AVINDEX_KEYFRAME);
}
} else if (!version && avio_rb16(pb) == 3) {
avio_skip(pb, 4);
--
2.34.1
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^ permalink raw reply [flat|nested] 4+ messages in thread* [FFmpeg-devel] [PATCH v2 2/2] avformat/mvdec: re-indent after last commit
2022-01-01 1:11 [FFmpeg-devel] [PATCH v2 0/2] avformat/mvdec: make audio stream conditional John-Paul Stewart
2022-01-01 1:11 ` [FFmpeg-devel] [PATCH v2 1/2] " John-Paul Stewart
@ 2022-01-01 1:11 ` John-Paul Stewart
2022-01-05 6:18 ` [FFmpeg-devel] [PATCH v2 0/2] avformat/mvdec: make audio stream conditional Peter Ross
2 siblings, 0 replies; 4+ messages in thread
From: John-Paul Stewart @ 2022-01-01 1:11 UTC (permalink / raw)
To: ffmpeg-devel
Signed-off-by: John-Paul Stewart <jpstewart@personalprojects.net>
---
libavformat/mvdec.c | 72 ++++++++++++++++++++++-----------------------
1 file changed, 36 insertions(+), 36 deletions(-)
diff --git a/libavformat/mvdec.c b/libavformat/mvdec.c
index 0f0474141b..4f233aff5f 100644
--- a/libavformat/mvdec.c
+++ b/libavformat/mvdec.c
@@ -316,9 +316,9 @@ static int mv_read_header(AVFormatContext *avctx)
v = avio_rb16(pb);
if (v == MOVIE_SOUND) {
/* movie has sound so allocate an audio stream */
- ast = avformat_new_stream(avctx, NULL);
- if (!ast)
- return AVERROR(ENOMEM);
+ ast = avformat_new_stream(avctx, NULL);
+ if (!ast)
+ return AVERROR(ENOMEM);
} else if (v != MOVIE_SILENT)
return AVERROR_INVALIDDATA;
@@ -350,41 +350,41 @@ static int mv_read_header(AVFormatContext *avctx)
avio_skip(pb, 12);
if (ast) {
- ast->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
- ast->nb_frames = vst->nb_frames;
- ast->codecpar->sample_rate = avio_rb32(pb);
- if (ast->codecpar->sample_rate <= 0) {
- av_log(avctx, AV_LOG_ERROR, "Invalid sample rate %d\n", ast->codecpar->sample_rate);
- return AVERROR_INVALIDDATA;
- }
- avpriv_set_pts_info(ast, 33, 1, ast->codecpar->sample_rate);
-
- bytes_per_sample = avio_rb32(pb);
-
- v = avio_rb32(pb);
- if (v == AUDIO_FORMAT_SIGNED) {
- switch (bytes_per_sample) {
- case 1:
- ast->codecpar->codec_id = AV_CODEC_ID_PCM_S8;
- break;
- case 2:
- ast->codecpar->codec_id = AV_CODEC_ID_PCM_S16BE;
- break;
- default:
- avpriv_request_sample(avctx, "Audio sample size %i bytes", bytes_per_sample);
- break;
+ ast->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
+ ast->nb_frames = vst->nb_frames;
+ ast->codecpar->sample_rate = avio_rb32(pb);
+ if (ast->codecpar->sample_rate <= 0) {
+ av_log(avctx, AV_LOG_ERROR, "Invalid sample rate %d\n", ast->codecpar->sample_rate);
+ return AVERROR_INVALIDDATA;
+ }
+ avpriv_set_pts_info(ast, 33, 1, ast->codecpar->sample_rate);
+
+ bytes_per_sample = avio_rb32(pb);
+
+ v = avio_rb32(pb);
+ if (v == AUDIO_FORMAT_SIGNED) {
+ switch (bytes_per_sample) {
+ case 1:
+ ast->codecpar->codec_id = AV_CODEC_ID_PCM_S8;
+ break;
+ case 2:
+ ast->codecpar->codec_id = AV_CODEC_ID_PCM_S16BE;
+ break;
+ default:
+ avpriv_request_sample(avctx, "Audio sample size %i bytes", bytes_per_sample);
+ break;
+ }
+ } else {
+ avpriv_request_sample(avctx, "Audio compression (format %i)", v);
}
- } else {
- avpriv_request_sample(avctx, "Audio compression (format %i)", v);
- }
- if (bytes_per_sample == 0)
- return AVERROR_INVALIDDATA;
+ if (bytes_per_sample == 0)
+ return AVERROR_INVALIDDATA;
- if (set_channels(avctx, ast, avio_rb32(pb)) < 0)
- return AVERROR_INVALIDDATA;
+ if (set_channels(avctx, ast, avio_rb32(pb)) < 0)
+ return AVERROR_INVALIDDATA;
- avio_skip(pb, 8);
+ avio_skip(pb, 8);
} else
avio_skip(pb, 24); /* skip meaningless audio metadata */
@@ -401,8 +401,8 @@ static int mv_read_header(AVFormatContext *avctx)
return AVERROR_INVALIDDATA;
avio_skip(pb, 8);
if (ast) {
- av_add_index_entry(ast, pos, timestamp, asize, 0, AVINDEX_KEYFRAME);
- timestamp += asize / (ast->codecpar->channels * (uint64_t)bytes_per_sample);
+ av_add_index_entry(ast, pos, timestamp, asize, 0, AVINDEX_KEYFRAME);
+ timestamp += asize / (ast->codecpar->channels * (uint64_t)bytes_per_sample);
}
av_add_index_entry(vst, pos + asize, i, vsize, 0, AVINDEX_KEYFRAME);
}
--
2.34.1
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^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [FFmpeg-devel] [PATCH v2 0/2] avformat/mvdec: make audio stream conditional
2022-01-01 1:11 [FFmpeg-devel] [PATCH v2 0/2] avformat/mvdec: make audio stream conditional John-Paul Stewart
2022-01-01 1:11 ` [FFmpeg-devel] [PATCH v2 1/2] " John-Paul Stewart
2022-01-01 1:11 ` [FFmpeg-devel] [PATCH v2 2/2] avformat/mvdec: re-indent after last commit John-Paul Stewart
@ 2022-01-05 6:18 ` Peter Ross
2 siblings, 0 replies; 4+ messages in thread
From: Peter Ross @ 2022-01-05 6:18 UTC (permalink / raw)
To: FFmpeg development discussions and patches
[-- Attachment #1.1: Type: text/plain, Size: 1027 bytes --]
On Fri, Dec 31, 2021 at 08:11:46PM -0500, John-Paul Stewart wrote:
> Changed in v2:
> Allocate the audio stream first to maintain consistent behaviour
> with prior code.
>
> Recent discussion on the list led me to realize that libavformat was
> unconditionally creating an audio stream for all SGI movie format
> (version 2) files, even when no audio is present in the file.
>
> A sample of a movie file with no audio can be found at
> http://www.personalprojects.net/ffmpeg/silent.movie
>
> Unpatched ffmpeg will report an audio stream even though no audio is
> present. After the following patch no audio stream is reported.
>
> Incidentally, the silent.movie sample above is at 25fps and can also be
> used by anyone who wants to double-check the earlier patch 3c9ffbd009
> that reads and sets the framerate. The sample file is only about 88 KB.
v2 patchset looks good to me. I will apply in a couple of days. Thanks.
-- Peter
(A907 E02F A6E5 0CD2 34CD 20D2 6760 79C5 AC40 DD6B)
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^ permalink raw reply [flat|nested] 4+ messages in thread