On 10/3/2018 8:26 PM, Mark Thompson wrote:
> On 03/10/18 02:44, James Almer wrote:
>> Simple parser to set keyframes, frame type, structure, width, height, and
>> pixel
>> format, plus stream profile and level.
>>
>> Signed-off-by: James Almer <jamr...@gmail.com>
>> ---
>> Missing Changelog entry and version bump still.
>>
>> configure | 1 +
>> libavcodec/Makefile | 1 +
>> libavcodec/av1_parser.c | 226 ++++++++++++++++++++++++++++++++++++++++
>> libavcodec/parsers.c | 1 +
>> 4 files changed, 229 insertions(+)
>> create mode 100644 libavcodec/av1_parser.c
>
> Looks good, and tested a bit (+1 for it removing the annoying need for
> -copyinkf when messing with BSFs in stream copy from raw IVF files).
>
> One very minor nitpick below, then no more from me :)
>
> Thanks,
>
> - Mark
>
>
>> ...
>> diff --git a/libavcodec/av1_parser.c b/libavcodec/av1_parser.c
>> new file mode 100644
>> index 0000000000..0dee3e9d2e
>> --- /dev/null
>> +++ b/libavcodec/av1_parser.c
>> ...
>> +
>> +static int av1_parser_parse(AVCodecParserContext *ctx,
>> + AVCodecContext *avctx,
>> + const uint8_t **out_data, int *out_size,
>> + const uint8_t *data, int size)
>> +{
>> + AV1ParseContext *s = ctx->priv_data;
>> + CodedBitstreamFragment *td = &s->temporal_unit;
>> + CodedBitstreamAV1Context *av1 = s->cbc->priv_data;
>> + int ret;
>> +
>> + *out_data = data;
>> + *out_size = size;
>> +
>> + ctx->key_frame = -1;
>> + ctx->pict_type = AV_PICTURE_TYPE_NONE;
>> + ctx->picture_structure = AV_PICTURE_STRUCTURE_UNKNOWN;
>> +
>> + s->cbc->log_ctx = avctx;
>
> I think this should be unset at the end of the function as well. While I
> don't see a way for it to do so currently, some later call like the
> ff_cbs_close() could in theory attempt to use the logging context and then
> invoke undefined behaviour because the AVCodecContext assigned here need not
> still be accessible.
Yeah, good catch. Changed and pushed, thanks!
We may need to start planning on a replacement parser API. The fact it
still uses raw bitstreams instead of AVPackets is a real handicap. Just
by having to use ff_cbs_read() instead of ff_cbs_read_packet() this
parser is slower than it should, because of the data memcpy.
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