[FFmpeg-devel] [PATCH] avformat/mxfenc: simplify dv ul handling

[Tomas Härdin]

lör 2019-11-09 klockan 15:46 -0800 skrev Baptiste Coudurier:
> +static const UID mxf_dv_container_uls[] = {
> +    { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x01,0x0D,0x01,0x03,0x01,0x02,0x02,0x01,0x01 }, // IEC DV25 525/60
> +    { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x01,0x0D,0x01,0x03,0x01,0x02,0x02,0x02,0x01 }, // IEC DV25 626/50
> +    { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x01,0x0D,0x01,0x03,0x01,0x02,0x02,0x40,0x01 }, // DV25 525/60
> +    { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x01,0x0D,0x01,0x03,0x01,0x02,0x02,0x41,0x01 }, // DV25 625/50
> +    { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x01,0x0D,0x01,0x03,0x01,0x02,0x02,0x50,0x01 }, // DV50 525/60
> +    { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x01,0x0D,0x01,0x03,0x01,0x02,0x02,0x51,0x01 }, // DV50 625/50
> +    { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x01,0x0D,0x01,0x03,0x01,0x02,0x02,0x60,0x01 }, // DV100 1080/60
> +    { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x01,0x0D,0x01,0x03,0x01,0x02,0x02,0x61,0x01 }, // DV100 1080/50
> +    { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x01,0x0D,0x01,0x03,0x01,0x02,0x02,0x62,0x01 }, // DV100 720/60
> +    { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x01,0x0D,0x01,0x03,0x01,0x02,0x02,0x63,0x01 }, // DV100 720/50
> +};
> +
> +static const UID mxf_dv_codec_uls[] = {
> +    { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x01,0x04,0x01,0x02,0x02,0x02,0x01,0x01,0x00 },
> +    { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x01,0x04,0x01,0x02,0x02,0x02,0x01,0x02,0x00 },
> +    { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x01,0x04,0x01,0x02,0x02,0x02,0x02,0x01,0x00 },
> +    { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x01,0x04,0x01,0x02,0x02,0x02,0x02,0x02,0x00 },
> +    { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x01,0x04,0x01,0x02,0x02,0x02,0x02,0x03,0x00 },
> +    { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x01,0x04,0x01,0x02,0x02,0x02,0x02,0x04,0x00 },
> +    { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x01,0x04,0x01,0x02,0x02,0x02,0x02,0x05,0x00 },
> +    { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x01,0x04,0x01,0x02,0x02,0x02,0x02,0x06,0x00 },
> +    { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x01,0x04,0x01,0x02,0x02,0x02,0x02,0x07,0x00 },
> +    { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x01,0x04,0x01,0x02,0x02,0x02,0x02,0x08,0x00 },
> +};

Maybe a struct to keep these two together, or a comment saying they
correspond to eachother 1:1

>  static int mxf_parse_dv_frame(AVFormatContext *s, AVStream *st, AVPacket *pkt)
>  {
>      MXFContext *mxf = s->priv_data;
>      MXFStreamContext *sc = st->priv_data;
>      uint8_t *vs_pack, *vsc_pack;
> +    int apt = pkt->data[4] & 0x7;

Can pkt->data ever be less than 5 bytes?

> @@ -2182,28 +2144,29 @@ static int mxf_parse_dv_frame(AVFormatContext *s, AVStream *st, AVPacket *pkt)
>  
>      switch (stype) {
>      case 0x18: // DV100 720p
> -        ul_index = INDEX_DV100_720_50 + pal;
> +        ul_index = 8+pal;

Not a huge fan of magic constants. Maybe just move the INDEX_DV* enums
to their own enum? Could use array index initializers to enforce that
they're indeed in the right spots in mxf_dv_*_uls[]. Combined with the
struct suggestion:

static const struct {
 UID container_ul, codec_ul;
} dv_uls[] = {
 [INDEX_DV25_525_60] = {{0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x01,0x0D,0x01,0x03,0x01,0x02,0x02,0x01,0x01},
                        {0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x01,0x04,0x01,0x02,0x02,0x02,0x01,0x01,0x00}},
 //...
};

/Tomas