[FFmpeg-devel] [PATCH 10/12] lavf/mxfdec: demux s436m as eia608 subtitle track

[Marton Balint]

On Wed, 4 Jul 2018, Baptiste Coudurier wrote:

> ---
> libavformat/mxfdec.c | 102 +++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 102 insertions(+)
>
> diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c
> index 3f443bbbc9..54e4be7934 100644
> --- a/libavformat/mxfdec.c
> +++ b/libavformat/mxfdec.c
> @@ -52,6 +52,7 @@
> #include "libavutil/intreadwrite.h"
> #include "libavutil/parseutils.h"
> #include "libavutil/timecode.h"
> +#include "libavutil/opt.h"
> #include "avformat.h"
> #include "internal.h"
> #include "mxf.h"
> @@ -263,6 +264,7 @@ typedef struct MXFIndexTable {
> } MXFIndexTable;
> 
> typedef struct MXFContext {
> +    const AVClass *class;     /**< Class for private options. */
>     MXFPartition *partitions;
>     unsigned partitions_count;
>     MXFOP op;
> @@ -287,6 +289,8 @@ typedef struct MXFContext {
>     int64_t current_edit_unit;
>     int nb_index_tables;
>     MXFIndexTable *index_tables;
> +    int edit_units_per_packet;      ///< how many edit units to read at a time (PCM, OPAtom)

This seems unused, probably remained after a merge. (edit_units_per_packet 
is now an MXFTrack property).

> +    int eia608_extract;
> } MXFContext;
> 
> /* NOTE: klv_offset is not set (-1) for local keys */
> @@ -449,6 +453,78 @@ static int find_body_sid_by_offset(MXFContext *mxf, int64_t offset)
>     return mxf->partitions[a].body_sid;
> }
> 
> +static int mxf_get_eia608_packet(AVFormatContext *s, AVStream *st, AVPacket *pkt, int64_t length)
> +{
> +    int count = avio_rb16(s->pb);
> +    int i, ret;
> +
> +    for (i = 0; i < count; i++) {
> +        if (length < 6) {
> +            av_log(s, AV_LOG_ERROR, "error reading s436m packet %"PRId64"\n", length);
> +            return AVERROR_INVALIDDATA;
> +        }
> +        int line_num = avio_rb16(s->pb);
> +        int wrapping_type = avio_r8(s->pb);
> +        int sample_coding = avio_r8(s->pb);
> +        int sample_count = avio_rb16(s->pb);
> +        av_log(s, AV_LOG_DEBUG, "len %"PRId64" line %d wrap type %d coding %d count %d\n",
> +               length, line_num, wrapping_type, sample_coding, sample_count);
> +        length -= 6 + 8 + sample_count;
> +        if (line_num != 9 && line_num != 11)
> +            break;
> +        if (sample_coding == 7 || sample_coding == 8 || sample_coding == 9) {
> +            av_log(s, AV_LOG_ERROR, "unsupported s436m 10 bit sample coding\n");
> +            return 0;
> +        }
> +        if (length < 0)
> +            return AVERROR_INVALIDDATA;
> +
> +        int array_count = avio_rb32(s->pb);
> +        int array_elem_size = avio_rb32(s->pb);
> +        av_log(s, AV_LOG_DEBUG, "array count %d elem size %d\n", array_count, array_elem_size);
> +        int did = avio_r8(s->pb);
> +        int sdid = avio_r8(s->pb);
> +        int data_count = avio_r8(s->pb);
> +        av_log(s, AV_LOG_DEBUG, "did %x sdid %x count %d\n", did, sdid, data_count);
> +        if (did != 0x61)
> +            break;
> +        int cdp_id = avio_rb16(s->pb);
> +        int cdp_data_count = avio_r8(s->pb);
> +        int cdp_framing_rate = avio_r8(s->pb) >> 4;
> +        int cdp_flags = avio_r8(s->pb);
> +        int cdp_counter = avio_rb16(s->pb);
> +        int cdp_data_section = avio_r8(s->pb);
> +        if (cdp_data_section != 0x72) {
> +            av_log(s, AV_LOG_ERROR, "wrong cdp data section %x\n", cdp_data_section);
> +            return AVERROR_INVALIDDATA;
> +        }
> +        int flags = avio_r8(s->pb);
> +        int cc_count = flags & 0x1f;
> +        av_log(s, AV_LOG_DEBUG, "cdp id %x dcount %d frame rate %d cdp flags %x flags %x "
> +               "cc count %d counter %d section %x\n", cdp_id, cdp_data_count, cdp_framing_rate,
> +               cdp_flags, flags, cc_count, cdp_counter, cdp_data_section);
> +        ret = av_get_packet(s->pb, pkt, cc_count * 3);
> +        if (ret < 0)
> +            return ret;
> +        if (cdp_data_count - 9 - 4 <  cc_count * 3) {
> +            av_log(s, AV_LOG_ERROR, "wrong cdp size %d cc count %d\n", data_count, cc_count);
> +            return AVERROR_INVALIDDATA;
> +        }
> +        avio_skip(s->pb, data_count - 9 - 4 - cc_count * 3);
> +        int cdp_footer_section = avio_r8(s->pb);
> +        if (cdp_footer_section != 0x74) {
> +            av_log(s, AV_LOG_ERROR, "wrong cdp footer section %x\n", cdp_footer_section);
> +            return AVERROR_INVALIDDATA;
> +        }
> +        int cdp_counter2 = avio_rb16(s->pb);
> +        int cdp_checksum = avio_r8(s->pb);
> +        av_log(s, AV_LOG_DEBUG, "cdp counter %d checksum %x\n", cdp_counter2, cdp_checksum);
> +        break;
> +    }
> +
> +    return 0;
> +}
> +
> /* XXX: use AVBitStreamFilter */
> static int mxf_get_d10_aes3_packet(AVIOContext *pb, AVStream *st, AVPacket *pkt, int64_t length)
> {
> @@ -2415,6 +2491,11 @@ static int mxf_parse_structural_metadata(MXFContext *mxf)
>                 st->codecpar->codec_type = type;
>             if (container_ul->desc)
>                 av_dict_set(&st->metadata, "data_type", container_ul->desc, 0);
> +            if (mxf->eia608_extract &&
> +                !strcmp(container_ul->desc, "vbi_vanc_smpte_436M")) {
> +                st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
> +                st->codecpar->codec_id = AV_CODEC_ID_EIA_608;
> +            }
>         }
>         if (descriptor->extradata) {
>             if (!ff_alloc_extradata(st->codecpar, descriptor->extradata_size)) {
> @@ -3356,6 +3437,11 @@ static int mxf_read_packet_old(AVFormatContext *s, AVPacket *pkt)
>                     av_log(s, AV_LOG_ERROR, "error reading D-10 aes3 frame\n");
>                     return ret;
>                 }
> +            } else if (mxf->eia608_extract &&
> +                       s->streams[index]->codecpar->codec_id == AV_CODEC_ID_EIA_608) {
> +                ret = mxf_get_eia608_packet(s, s->streams[index], pkt, klv.length);
> +                if (ret < 0)
> +                    return ret;

After my clip wrapped patches this probably needs to be:

                    if (ret < 0) {
                        mxf->current_klv_data = (KLVPacket){{0}};
                        return ret;
                    }

Thanks,
Marton