[FFmpeg-devel] [PATCH] avformat/framecrcenc: support calculating checksum of IAMF side data

[Andreas Rheinhardt]

James Almer:
> The total allocated size for types is arch dependent, so instead calculate a
> checksum of the fields only.
> 
> Signed-off-by: James Almer <jamrial at gmail.com>
> ---
> Depends on "[PATCH v3] avformat/framecrcenc: compute the checksum for side data"
> 
>  libavformat/framecrcenc.c | 76 ++++++++++++++++++++++++++++++++++++---
>  1 file changed, 71 insertions(+), 5 deletions(-)
> 
> diff --git a/libavformat/framecrcenc.c b/libavformat/framecrcenc.c
> index 8cc4a93053..6d46b51489 100644
> --- a/libavformat/framecrcenc.c
> +++ b/libavformat/framecrcenc.c
> @@ -24,6 +24,7 @@
>  #include "config.h"
>  #include "libavutil/adler32.h"
>  #include "libavutil/avstring.h"
> +#include "libavutil/iamf.h"
>  #include "libavutil/intreadwrite.h"
>  
>  #include "libavcodec/codec_id.h"
> @@ -76,7 +77,8 @@ static int framecrc_write_packet(struct AVFormatContext *s, AVPacket *pkt)
>          for (int i = 0; i < pkt->side_data_elems; i++) {
>              const AVPacketSideData *const sd = &pkt->side_data[i];
>              const uint8_t *data = sd->data;
> -            int64_t side_data_crc = 0;
> +            size_t size = sd->size;
> +            uint32_t side_data_crc = 0;
>  
>              switch (sd->type) {
>  #if HAVE_BIGENDIAN
> @@ -127,12 +129,76 @@ static int framecrc_write_packet(struct AVFormatContext *s, AVPacket *pkt)
>              case AV_PKT_DATA_IAMF_MIX_GAIN_PARAM:
>              case AV_PKT_DATA_IAMF_DEMIXING_INFO_PARAM:
>              case AV_PKT_DATA_IAMF_RECON_GAIN_INFO_PARAM:
> -                side_data_crc = -1;
> +            {
> +                const AVIAMFParamDefinition *param = (AVIAMFParamDefinition *)sd->data;
> +                uint8_t buf[8];
> +                ptrdiff_t offset = 0;
> +                size = 0;
> +#define READ_UINT32(struct, parent, child) do { \
> +    if ((offset + offsetof(struct, child) + sizeof(parent->child)) > sd->size) \
> +        goto iamf_end; \
> +    AV_WL32(buf, parent->child); \
> +    side_data_crc = av_adler32_update(side_data_crc, buf, 4); \
> +    size += 4; \
> +} while (0)
> +#define READ_RATIONAL(struct, parent, child) do { \
> +    if ((offset + offsetof(struct, child) + sizeof(parent->child)) > sd->size) \
> +        goto iamf_end; \
> +    AV_WL32(buf + 0, parent->child.num); \
> +    AV_WL32(buf + 4, parent->child.den); \
> +    side_data_crc = av_adler32_update(side_data_crc, buf, 8); \
> +    size += 8; \
> +} while (0)
> +                READ_UINT32(AVIAMFParamDefinition, param, nb_subblocks);
> +                READ_UINT32(AVIAMFParamDefinition, param, type);
> +                READ_UINT32(AVIAMFParamDefinition, param, parameter_id);
> +                READ_UINT32(AVIAMFParamDefinition, param, parameter_rate);
> +                READ_UINT32(AVIAMFParamDefinition, param, duration);
> +                READ_UINT32(AVIAMFParamDefinition, param, constant_subblock_duration);
> +                for (unsigned int i = 0; i < param->nb_subblocks; i++) {
> +                    void *subblock = av_iamf_param_definition_get_subblock(param, i);
> +
> +                    offset = (intptr_t)subblock - (intptr_t)sd->data;
> +                    switch (param->type) {
> +                    case AV_IAMF_PARAMETER_DEFINITION_MIX_GAIN: {
> +                        const AVIAMFMixGain *mix = subblock;
> +                        READ_UINT32(AVIAMFMixGain, mix, subblock_duration);
> +                        READ_UINT32(AVIAMFMixGain, mix, animation_type);
> +                        READ_RATIONAL(AVIAMFMixGain, mix, start_point_value);
> +                        READ_RATIONAL(AVIAMFMixGain, mix, end_point_value);
> +                        READ_RATIONAL(AVIAMFMixGain, mix, control_point_value);
> +                        READ_RATIONAL(AVIAMFMixGain, mix, control_point_relative_time);
> +                        break;
> +                    }
> +                    case AV_IAMF_PARAMETER_DEFINITION_DEMIXING: {
> +                        const AVIAMFDemixingInfo *demix = subblock;
> +                        READ_UINT32(AVIAMFDemixingInfo, demix, subblock_duration);
> +                        READ_UINT32(AVIAMFDemixingInfo, demix, dmixp_mode);
> +                        break;
> +                    }
> +                    case AV_IAMF_PARAMETER_DEFINITION_RECON_GAIN: {
> +                        const AVIAMFReconGain *recon = subblock;
> +                        READ_UINT32(AVIAMFReconGain, recon, subblock_duration);
> +                        if ((offset + offsetof(AVIAMFReconGain, recon_gain)
> +                                    + sizeof(recon->recon_gain)) > sd->size)
> +                            goto iamf_end;
> +                        side_data_crc = av_adler32_update(side_data_crc,
> +                                                          (uint8_t *)recon->recon_gain,
> +                                                          sizeof(recon->recon_gain));
> +                        size += sizeof(recon->recon_gain);
> +                        break;
> +                    }
> +                    default:
> +                        break;
> +                    }
> +                }
> +                iamf_end:
> +                break;
> +            }
>              }
>  
> -            av_strlcatf(buf, sizeof(buf), ", T=%2d, %8"SIZE_SPECIFIER, pkt->side_data[i].type, pkt->side_data[i].size);
> -            if (side_data_crc >= 0)
> -                av_strlcatf(buf, sizeof(buf), ", 0x%08"PRIx32, (uint32_t)side_data_crc);
> +            av_strlcatf(buf, sizeof(buf), ", T=%2d, %8"SIZE_SPECIFIER, pkt->side_data[i].type, size);
> +            av_strlcatf(buf, sizeof(buf), ", 0x%08"PRIx32, side_data_crc);
>          }
>      }
>      av_strlcatf(buf, sizeof(buf), "\n");

This is overkill; tests for IAMF side data should use ffprobe.

- Andreas