On 28 Apr 2025, at 13:00, Dimitry Andric <dimi...@unified-streaming.com> wrote:
>
> On 19 Apr 2025, at 16:27, Dimitry Andric <dimi...@unified-streaming.com>
> wrote:
>>
>> On 10 Apr 2025, at 11:03, Dimitry Andric <dimi...@unified-streaming.com>
>> wrote:
>>>
>>> On 3 Apr 2025, at 22:02, Dimitry Andric <dimi...@unified-streaming.com>
>>> wrote:
>>>>
>>>> When decoding fragmented MP4 files that have an empty stsc box, and
>>>> instead contain sample description indexes in their tfhd boxes, the mov
>>>> demuxer does not notify the decoder whenever the current sample
>>>> description index changes. If the SPS or PPS changed sufficiently, this
>>>> can lead to unexpected decoding errors.
>>>>
>>>> To fix this, in mov_finalize_packet(), when stsc_data is not available,
>>>> use get_frag_stream_info_from_pkt() to get at the current fragment
>>>> stream info, and retrieve the current sample description index from
>>>> there. Then use that index in a similar manner as the stsc case.
>>>>
>>>> Signed-off-by: Dimitry Andric <dimi...@unified-streaming.com>
>>>> ---
>>>> libavformat/mov.c | 50 ++++++++++++++++++++++++++++-------------------
>>>> 1 file changed, 30 insertions(+), 20 deletions(-)
>>>>
>>>> diff --git a/libavformat/mov.c b/libavformat/mov.c
>>>> index 452690090c..ead89192f4 100644
>>>> --- a/libavformat/mov.c
>>>> +++ b/libavformat/mov.c
>>>> @@ -10756,25 +10756,29 @@ static int mov_switch_root(AVFormatContext *s,
>>>> int64_t target, int index)
>>>> return 1;
>>>> }
>>>>
>>>> -static int mov_change_extradata(AVStream *st, AVPacket *pkt)
>>>> +static int mov_change_extradata(AVStream *st, AVPacket *pkt, int stsd_id)
>>>> {
>>>> MOVStreamContext *sc = st->priv_data;
>>>> uint8_t *side, *extradata;
>>>> int extradata_size;
>>>>
>>>> - /* Save the current index. */
>>>> - sc->last_stsd_index = sc->stsc_data[sc->stsc_index].id - 1;
>>>> + if (stsd_id > 0 &&
>>>> + stsd_id - 1 < sc->stsd_count &&
>>>> + stsd_id - 1 != sc->last_stsd_index) {
>>>> + /* Save the current index. */
>>>> + sc->last_stsd_index = stsd_id - 1;
>>>>
>>>> - /* Notify the decoder that extradata changed. */
>>>> - extradata_size = sc->extradata_size[sc->last_stsd_index];
>>>> - extradata = sc->extradata[sc->last_stsd_index];
>>>> - if (st->discard != AVDISCARD_ALL && extradata_size > 0 && extradata) {
>>>> - side = av_packet_new_side_data(pkt,
>>>> - AV_PKT_DATA_NEW_EXTRADATA,
>>>> - extradata_size);
>>>> - if (!side)
>>>> - return AVERROR(ENOMEM);
>>>> - memcpy(side, extradata, extradata_size);
>>>> + /* Notify the decoder that extradata changed. */
>>>> + extradata_size = sc->extradata_size[sc->last_stsd_index];
>>>> + extradata = sc->extradata[sc->last_stsd_index];
>>>> + if (st->discard != AVDISCARD_ALL && extradata_size > 0 &&
>>>> extradata) {
>>>> + side = av_packet_new_side_data(pkt,
>>>> + AV_PKT_DATA_NEW_EXTRADATA,
>>>> + extradata_size);
>>>> + if (!side)
>>>> + return AVERROR(ENOMEM);
>>>> + memcpy(side, extradata, extradata_size);
>>>> + }
>>>> }
>>>>
>>>> return 0;
>>>> @@ -10893,13 +10897,10 @@ static int mov_finalize_packet(AVFormatContext
>>>> *s, AVStream *st, AVIndexEntry *s
>>>>
>>>> /* Multiple stsd handling. */
>>>> if (sc->stsc_data) {
>>>> - if (sc->stsc_data[sc->stsc_index].id > 0 &&
>>>> - sc->stsc_data[sc->stsc_index].id - 1 < sc->stsd_count &&
>>>> - sc->stsc_data[sc->stsc_index].id - 1 != sc->last_stsd_index) {
>>>> - int ret = mov_change_extradata(st, pkt);
>>>> - if (ret < 0)
>>>> - return ret;
>>>> - }
>>>> + int stsd_id = sc->stsc_data[sc->stsc_index].id;
>>>> + int ret = mov_change_extradata(st, pkt, stsd_id);
>>>> + if (ret < 0)
>>>> + return ret;
>>>>
>>>> /* Update the stsc index for the next sample */
>>>> sc->stsc_sample++;
>>>> @@ -10908,6 +10909,15 @@ static int mov_finalize_packet(AVFormatContext
>>>> *s, AVStream *st, AVIndexEntry *s
>>>> sc->stsc_index++;
>>>> sc->stsc_sample = 0;
>>>> }
>>>> + } else {
>>>> + MOVContext *mov = s->priv_data;
>>>> + MOVFragmentStreamInfo *frag_stream_info =
>>>> get_frag_stream_info_from_pkt(&mov->frag_index, pkt, sc->id);
>>>> + if (frag_stream_info) {
>>>> + int stsd_id = frag_stream_info->stsd_id;
>>>> + int ret = mov_change_extradata(st, pkt, stsd_id);
>>>> + if (ret < 0)
>>>> + return ret;
>>>> + }
>>>> }
>>>>
>>>> return 0;
>>>> --
>>>> 2.43.0
>>>>
>>>
>>> Any comments on this patch?
>>
>> Ping :)
>
> Is there any particular group of persons that "own" the mov muxer?
Another ping.
-Dimitry
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