[FFmpeg-devel] avformat/movenc: allow rewriting extradata

[Umair Khan]

Hi,

On Thu, Aug 18, 2016 at 2:10 AM, Umair Khan <omerjerk at gmail.com> wrote:
> On Thu, Aug 18, 2016 at 1:28 AM, James Almer <jamrial at gmail.com> wrote:
>> On 8/17/2016 3:59 PM, Umair Khan wrote:
>>> Hi,
>>>
>>> Patch attached.
>>>
>>> I hope this is the cleanest solution. :)
>>>
>>> - Umair
>>>
>>>
>>> patch.diff
>>>
>>>
>>> From be04357d54897173b1776ed92ab8347b3cdffd46 Mon Sep 17 00:00:00 2001
>>> From: Umair Khan <omerjerk at gmail.com>
>>> Date: Thu, 18 Aug 2016 00:27:42 +0530
>>> Subject: [PATCH] avformat/movenc: allow rewriting extradata
>>>
>>> Signed-off-by: Umair Khan <omerjerk at gmail.com>
>>> ---
>>>  libavformat/movenc.c | 30 ++++++++++++++++++++++++++++++
>>>  libavformat/movenc.h |  2 ++
>>>  2 files changed, 32 insertions(+)
>>>
>>> diff --git a/libavformat/movenc.c b/libavformat/movenc.c
>>> index 14db880..b33f24c 100644
>>> --- a/libavformat/movenc.c
>>> +++ b/libavformat/movenc.c
>>> @@ -4919,6 +4919,19 @@ static int mov_write_single_packet(AVFormatContext *s, AVPacket *pkt)
>>>                      trk->start_cts = pkt->pts - pkt->dts;
>>>                  else
>>>                      trk->start_cts = 0;
>>> +            }
>>> +
>>> +            if (trk->par->codec_id == AV_CODEC_ID_MP4ALS) {
>>> +                int side_size = 0;
>>> +                uint8_t *side = av_packet_get_side_data(pkt, AV_PKT_DATA_NEW_EXTRADATA, &side_size);
>>> +                av_log(s, AV_LOG_ERROR, "side_size = %d\n", side_size);
>>
>> I'm not sure this is useful at all, but if you think it is
>> then make it either AV_ERROR_VERBOSE or AV_ERROR_DEBUG.
>
> Sorry for this. I overlooked it.
> I'll resend the patch.

Updated patch attached.

- Umair
-------------- next part --------------
From 3bda0c5d727e7b1f45e8fddc8c0022c0a1d5e66a Mon Sep 17 00:00:00 2001
From: Umair Khan <omerjerk at gmail.com>
Date: Thu, 18 Aug 2016 00:27:42 +0530
Subject: [PATCH] avformat/movenc: allow rewriting extradata

Signed-off-by: Umair Khan <omerjerk at gmail.com>
---
 libavformat/movenc.c | 28 ++++++++++++++++++++++++++++
 libavformat/movenc.h |  2 ++
 2 files changed, 30 insertions(+)

diff --git a/libavformat/movenc.c b/libavformat/movenc.c
index 14db880..1235b37 100644
--- a/libavformat/movenc.c
+++ b/libavformat/movenc.c
@@ -4919,6 +4919,18 @@ static int mov_write_single_packet(AVFormatContext *s, AVPacket *pkt)
                     trk->start_cts = pkt->pts - pkt->dts;
                 else
                     trk->start_cts = 0;
+            }       
+
+            if (trk->par->codec_id == AV_CODEC_ID_MP4ALS) {
+                int side_size = 0;
+                uint8_t *side = av_packet_get_side_data(pkt, AV_PKT_DATA_NEW_EXTRADATA, &side_size);
+                if (side && side_size > 0 && (side_size != par->extradata_size || memcmp(side, par->extradata, side_size))) {
+                    av_free(par->extradata);
+                    par->extradata = av_mallocz(side_size + AV_INPUT_BUFFER_PADDING_SIZE);
+                    memcpy(par->extradata, side, side_size);
+                    par->extradata_size = side_size;
+                    mov->need_rewrite_extradata = 1;
+                }
             }
 
             return 0;             /* Discard 0 sized packets */
@@ -5923,6 +5935,22 @@ static int mov_write_trailer(AVFormatContext *s)
     int i;
     int64_t moov_pos;
 
+    if (mov->need_rewrite_extradata) {
+        for (i = 0; i < s->nb_streams; i++) {
+            MOVTrack *track= &mov->tracks[i];
+            AVCodecParameters *par = track->par;
+
+            track->vos_len  = par->extradata_size;
+            track->vos_data = av_malloc(track->vos_len);
+            if (!track->vos_data) {
+                AVERROR(ENOMEM);
+                goto error;
+            }
+            memcpy(track->vos_data, par->extradata, track->vos_len);
+        }
+        mov->need_rewrite_extradata = 0;
+    }
+
     /*
      * Before actually writing the trailer, make sure that there are no
      * dangling subtitles, that need a terminating sample.
diff --git a/libavformat/movenc.h b/libavformat/movenc.h
index 6e9f5ac..894a1b0 100644
--- a/libavformat/movenc.h
+++ b/libavformat/movenc.h
@@ -215,6 +215,8 @@ typedef struct MOVMuxContext {
     uint8_t *encryption_kid;
     int encryption_kid_len;
 
+    int need_rewrite_extradata;
+
 } MOVMuxContext;
 
 #define FF_MOV_FLAG_RTP_HINT              (1 <<  0)
-- 
2.8.1