On 15/06/18 01:52, Xiang, Haihao wrote:
> On Fri, 2018-06-08 at 00:43 +0100, Mark Thompson wrote:
>> ---
>> configure | 2 +
>> libavcodec/Makefile | 1 +
>> libavcodec/cbs.c | 6 +
>> libavcodec/cbs_internal.h | 1 +
>> libavcodec/cbs_jpeg.c | 513
>> ++++++++++++++++++++++++++++++++++
>> libavcodec/cbs_jpeg.h | 128 +++++++++
>> libavcodec/cbs_jpeg_syntax_template.c | 191 +++++++++++++
>> 7 files changed, 842 insertions(+)
>> create mode 100644 libavcodec/cbs_jpeg.c
>> create mode 100644 libavcodec/cbs_jpeg.h
>> create mode 100644 libavcodec/cbs_jpeg_syntax_template.c
>>
>> ...
>> diff --git a/libavcodec/cbs_jpeg.c b/libavcodec/cbs_jpeg.c
>> new file mode 100644
>> index 0000000000..365db73394
>> --- /dev/null
>> +++ b/libavcodec/cbs_jpeg.c
>> ...
>> +static int cbs_jpeg_read_unit(CodedBitstreamContext *ctx,
>> + CodedBitstreamUnit *unit)
>> +{
>> + GetBitContext gbc;
>> + int err;
>> +
>> + err = init_get_bits(&gbc, unit->data, 8 * unit->data_size);
>> + if (err < 0)
>> + return err;
>> +
>> + if (unit->type >= JPEG_MARKER_SOF0 &&
>> + unit->type <= JPEG_MARKER_SOF3) {
>> + err = ff_cbs_alloc_unit_content(ctx, unit,
>> + sizeof(JPEGRawFrameHeader),
>> + NULL);
>> + if (err < 0)
>> + return err;
>> +
>> + err = cbs_jpeg_read_frame_header(ctx, &gbc, unit->content);
>> + if (err < 0)
>> + return err;
>> +
>> + } else if (unit->type >= JPEG_MARKER_APPN &&
>> + unit->type <= JPEG_MARKER_APPN + 15) {
>> + err = ff_cbs_alloc_unit_content(ctx, unit,
>> + sizeof(JPEGRawApplicationData),
>> + &cbs_jpeg_free_application_data);
>> + if (err < 0)
>> + return err;
>> +
>> + err = cbs_jpeg_read_application_data(ctx, &gbc, unit->content);
>> + if (err < 0)
>> + return err;
>> +
>> + } else if (unit->type == JPEG_MARKER_SOS) {
>> + JPEGRawScan *scan;
>> + int pos;
>> +
>> + err = ff_cbs_alloc_unit_content(ctx, unit,
>> + sizeof(JPEGRawScan),
>> + &cbs_jpeg_free_scan);
>> + if (err < 0)
>> + return err;
>> + scan = unit->content;
>> +
>> + err = cbs_jpeg_read_scan_header(ctx, &gbc, &scan->header);
>> + if (err < 0)
>> + return err;
>> +
>> + pos = get_bits_count(&gbc);
>> + av_assert0(pos % 8 == 0);
>> + if (pos > 0) {
>> + scan->data_size = unit->data_size - pos / 8;
>> + scan->data_ref = av_buffer_ref(unit->data_ref);
>> + if (!scan->data_ref)
>> + return AVERROR(ENOMEM);
>> + scan->data = unit->data + pos / 8;
>> + }
>> +
>> + } else {
>> + switch (unit->type) {
>> +#define SEGMENT(marker, type, func) \
>> + case JPEG_MARKER_ ## marker: \
>> + { \
>> + err = ff_cbs_alloc_unit_content(ctx, unit, \
>> + sizeof(type), NULL); \
>> + if (err < 0) \
>> + return err; \
>> + err = cbs_jpeg_read_ ## func(ctx, &gbc, unit->content); \
>> + if (err < 0) \
>> + return err; \
>> + } \
>> + break
>> + SEGMENT(DQT, JPEGRawQuantisationTableSpecification, dqt);
>> + SEGMENT(DHT, JPEGRawHuffmanTableSpecification, dht);
>> + SEGMENT(COM, JPEGRawComment, comment);
>
> A free function should be provided for JPEGRawComment as JPEGRawComment
> includes
> a AVBufferRef pointer.
Yep, fixed.
>> +#undef SEGMENT
>> + default:
>> + return AVERROR(ENOSYS);
>> + }
>> + }
>> +
>> + return 0;
>> +}
>> ...
Thanks,
- Mark
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