[FFmpeg-devel] [PATCH 3/4] avformat/mpegenc - accept PCM_DVD streams

[Gyan Doshi]

On 1/29/2018 6:53 PM, Gyan Doshi wrote:
> 
> On 1/29/2018 3:47 PM, Carl Eugen Hoyos wrote:
> 
>> How did you test this patch?
> 
> By remuxing with patched ffmpeg and then checking with ffprobe, but not 
> ffplay!
...
> Sorry, I'll rework and submit.

Revised and tested patch attached.
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From 78757309bbfbc9d9e48aabd6babc9529f83d5950 Mon Sep 17 00:00:00 2001
From: Gyan Doshi <gyandoshi at gmail.com>
Date: Thu, 1 Feb 2018 19:12:03 +0530
Subject: [PATCH v2] avformat/mpegenc - accept PCM_DVD streams

PCM_S16BE stream packets in MPEG-PS have a 3-byte header
and recognized as PCM_DVD by the demuxer which prevents
their proper remuxing in MPEG-1/2 PS.
---
 libavformat/mpegenc.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/libavformat/mpegenc.c b/libavformat/mpegenc.c
index c77c3dfe41..598df662f4 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 +364,10 @@ 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->codec_id == AV_CODEC_ID_PCM_DVD)
+                    av_log(ctx, AV_LOG_WARNING, "Only 16-bit LPCM streams are supported.\n");
                 stream->id = lpcm_id++;
                 for (j = 0; j < 4; j++) {
                     if (lpcm_freq_tab[j] == st->codecpar->sample_rate)
@@ -1150,8 +1154,17 @@ 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) {
+        /* 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)
         stream->predecode_packet = pkt_desc;
     stream->next_packet = &pkt_desc->next;
-- 
2.11.1.windows.1