[FFmpeg-devel] [PATCH 01/13] lavc/adpcm: THP: handle packets with sample counts not divisible by 14

[James Almer]

On 18/06/15 6:02 AM, Rodger Combs wrote:
> ---
>  libavcodec/adpcm.c | 18 +++++++++++++-----
>  1 file changed, 13 insertions(+), 5 deletions(-)
> 
> diff --git a/libavcodec/adpcm.c b/libavcodec/adpcm.c
> index 22b5468..1b35029 100644
> --- a/libavcodec/adpcm.c
> +++ b/libavcodec/adpcm.c
> @@ -642,9 +642,17 @@ static int get_nb_samples(AVCodecContext *avctx, GetByteContext *gb,
>          }
>          has_coded_samples = 1;
>          bytestream2_skip(gb, 4); // channel size
> -        *coded_samples  = bytestream2_get_be32(gb);
> -        *coded_samples -= *coded_samples % 14;
> -        nb_samples      = (buf_size - (8 + 36 * ch)) / (8 * ch) * 14;
> +        *coded_samples  = (avctx->codec->id == AV_CODEC_ID_ADPCM_THP_LE) ?

Leave it as bytestream2_get_be32(gb) for this patch, then add the thp_le check in the next,
where AV_CODEC_ID_ADPCM_THP_LE is introduced.

> +                          bytestream2_get_le32(gb) :
> +                          bytestream2_get_be32(gb);
> +        buf_size       -= 8 + 36 * ch;
> +        buf_size       /= ch;
> +        nb_samples      = buf_size / 8 * 14;
> +        if (buf_size % 8 > 1) {
> +            nb_samples     += (buf_size % 8 - 1) * 2;
> +            if (*coded_samples & 1)
> +                nb_samples -= 1;
> +        }
>          break;
>      case AV_CODEC_ID_ADPCM_AFC:
>          nb_samples = buf_size / (9 * ch) * 16;
> @@ -1446,7 +1454,7 @@ static int adpcm_decode_frame(AVCodecContext *avctx, void *data,
>              samples = samples_p[ch];
>  
>              /* Read in every sample for this channel.  */
> -            for (i = 0; i < nb_samples / 14; i++) {
> +            for (i = 0; i < (nb_samples + 13) / 14; i++) {
>                  int byte = bytestream2_get_byteu(&gb);
>                  int index = (byte >> 4) & 7;
>                  unsigned int exp = byte & 0x0F;
> @@ -1454,7 +1462,7 @@ static int adpcm_decode_frame(AVCodecContext *avctx, void *data,
>                  int factor2 = table[ch][index * 2 + 1];
>  
>                  /* Decode 14 samples.  */
> -                for (n = 0; n < 14; n++) {
> +                for (n = 0; n < 14 && (i * 14 + n < nb_samples); n++) {
>                      int32_t sampledat;
>  
>                      if (n & 1) {
>