[FFmpeg-devel] [PATCH 3/4] avformat/mpegenc - accept PCM_DVD streams
Gyan Doshi
gyandoshi at gmail.com
Mon Feb 12 21:03:56 EET 2018
On 2/3/2018 4:02 AM, Michael Niedermayer wrote:
>> --- a/libavformat/mpegenc.c
>> +++ b/libavformat/mpegenc.c
>> +
>> + if (st->codecpar->codec_id == AV_CODEC_ID_PCM_DVD) {
>> + /* Skip first 3 bytes of packet data, which comprise PCM header
>> + and will be written fresh by this muxer. */
>> + buf += 3;
>> + size -= 3;
>
> Can this be reached with size < 3 ?
> if so it would probably do something bad
Possible if input file is badly muxed, but revised patch attached.
FATE patch follows in next email.
Regards,
Gyan
-------------- next part --------------
From 75d6236f1964d014f615acf4dc48dec43cadf6a1 Mon Sep 17 00:00:00 2001
From: Gyan Doshi <gyandoshi at gmail.com>
Date: Wed, 7 Feb 2018 18:05:08 +0530
Subject: [PATCH v3] avformat/mpegenc - accept PCM_DVD streams
PCM_S16BE stream packets in MPEG-PS have a 3-byte header and
are recognized as PCM_DVD by the demuxer which prevents their
correct remuxing in MPEG-1/2 PS.
---
libavformat/mpegenc.c | 23 +++++++++++++++++++++--
1 file changed, 21 insertions(+), 2 deletions(-)
diff --git a/libavformat/mpegenc.c b/libavformat/mpegenc.c
index 695de3f081..895873accd 100644
--- a/libavformat/mpegenc.c
+++ b/libavformat/mpegenc.c
@@ -353,7 +353,8 @@ static av_cold int mpeg_mux_init(AVFormatContext *ctx)
if (!s->is_mpeg2 &&
(st->codecpar->codec_id == AV_CODEC_ID_AC3 ||
st->codecpar->codec_id == AV_CODEC_ID_DTS ||
- st->codecpar->codec_id == AV_CODEC_ID_PCM_S16BE))
+ st->codecpar->codec_id == AV_CODEC_ID_PCM_S16BE ||
+ st->codecpar->codec_id == AV_CODEC_ID_PCM_DVD))
av_log(ctx, AV_LOG_WARNING,
"%s in MPEG-1 system streams is not widely supported, "
"consider using the vob or the dvd muxer "
@@ -363,7 +364,12 @@ static av_cold int mpeg_mux_init(AVFormatContext *ctx)
stream->id = ac3_id++;
} else if (st->codecpar->codec_id == AV_CODEC_ID_DTS) {
stream->id = dts_id++;
- } else if (st->codecpar->codec_id == AV_CODEC_ID_PCM_S16BE) {
+ } else if (st->codecpar->codec_id == AV_CODEC_ID_PCM_S16BE ||
+ st->codecpar->codec_id == AV_CODEC_ID_PCM_DVD) {
+ if (st->codecpar->bits_per_coded_sample != 16) {
+ av_log(ctx, AV_LOG_ERROR, "Only 16 bit LPCM streams can be muxed.\n");
+ goto fail;
+ }
stream->id = lpcm_id++;
for (j = 0; j < 4; j++) {
if (lpcm_freq_tab[j] == st->codecpar->sample_rate)
@@ -1150,6 +1156,19 @@ static int mpeg_mux_write_packet(AVFormatContext *ctx, AVPacket *pkt)
return AVERROR(ENOMEM);
pkt_desc->pts = pts;
pkt_desc->dts = dts;
+
+ if (st->codecpar->codec_id == AV_CODEC_ID_PCM_DVD) {
+ if (size < 3) {
+ av_log(ctx, AV_LOG_ERROR, "Invalid packet size %d\n", size);
+ return -1;
+ }
+
+ /* Skip first 3 bytes of packet data, which comprise PCM header
+ and will be written fresh by this muxer. */
+ buf += 3;
+ size -= 3;
+ }
+
pkt_desc->unwritten_size =
pkt_desc->size = size;
if (!stream->predecode_packet)
--
2.11.1.windows.1
More information about the ffmpeg-devel
mailing list