From: Zhao Zhili <zhiliz...@tencent.com> start_code_size depends on whether PS comes from out-of-band or in-band. Make the code more readable. --- libavcodec/h264_mp4toannexb_bsf.c | 34 ++++++++++++++++++++++++------- 1 file changed, 27 insertions(+), 7 deletions(-)
diff --git a/libavcodec/h264_mp4toannexb_bsf.c b/libavcodec/h264_mp4toannexb_bsf.c index d11be455c2..7dce1ae9b6 100644 --- a/libavcodec/h264_mp4toannexb_bsf.c +++ b/libavcodec/h264_mp4toannexb_bsf.c @@ -43,10 +43,26 @@ typedef struct H264BSFContext { int extradata_parsed; } H264BSFContext; +enum PsSource { + PS_OUT_OF_BAND = -1, + PS_NONE = 0, + PS_IN_BAND = 1, +}; + static void count_or_copy(uint8_t **out, uint64_t *out_size, - const uint8_t *in, int in_size, int ps, int copy) + const uint8_t *in, int in_size, enum PsSource ps, int copy) { - uint8_t start_code_size = ps < 0 ? 0 : *out_size == 0 || ps ? 4 : 3; + uint8_t start_code_size; + + if (ps == PS_OUT_OF_BAND) + /* start code already present in out-of-band ps data, so don't need to + * add it manually again + */ + start_code_size = 0; + else if (ps == PS_IN_BAND || *out_size == 0) + start_code_size = 4; + else + start_code_size = 3; if (copy) { memcpy(*out + start_code_size, in, in_size); @@ -202,6 +218,7 @@ static int h264_mp4toannexb_filter(AVBSFContext *ctx, AVPacket *opkt) do { uint32_t nal_size = 0; + enum PsSource ps; /* possible overread ok due to padding */ for (int i = 0; i < s->length_size; i++) @@ -230,7 +247,7 @@ static int h264_mp4toannexb_filter(AVBSFContext *ctx, AVPacket *opkt) if (!s->sps_size) { LOG_ONCE(ctx, AV_LOG_WARNING, "SPS not present in the stream, nor in AVCC, stream may be unreadable\n"); } else { - count_or_copy(&out, &out_size, s->sps, s->sps_size, -1, j); + count_or_copy(&out, &out_size, s->sps, s->sps_size, PS_OUT_OF_BAND, j); sps_seen = 1; } } @@ -246,19 +263,22 @@ static int h264_mp4toannexb_filter(AVBSFContext *ctx, AVPacket *opkt) if (new_idr && unit_type == H264_NAL_IDR_SLICE && !sps_seen && !pps_seen) { if (ctx->par_out->extradata) count_or_copy(&out, &out_size, ctx->par_out->extradata, - ctx->par_out->extradata_size, -1, j); + ctx->par_out->extradata_size, PS_OUT_OF_BAND, j); new_idr = 0; /* if only SPS has been seen, also insert PPS */ } else if (new_idr && unit_type == H264_NAL_IDR_SLICE && sps_seen && !pps_seen) { if (!s->pps_size) { LOG_ONCE(ctx, AV_LOG_WARNING, "PPS not present in the stream, nor in AVCC, stream may be unreadable\n"); } else { - count_or_copy(&out, &out_size, s->pps, s->pps_size, -1, j); + count_or_copy(&out, &out_size, s->pps, s->pps_size, PS_OUT_OF_BAND, j); } } - count_or_copy(&out, &out_size, buf, nal_size, - unit_type == H264_NAL_SPS || unit_type == H264_NAL_PPS, j); + if (unit_type == H264_NAL_SPS || unit_type == H264_NAL_PPS) + ps = PS_IN_BAND; + else + ps = PS_NONE; + count_or_copy(&out, &out_size, buf, nal_size, ps, j); if (!new_idr && unit_type == H264_NAL_SLICE) { new_idr = 1; sps_seen = 0; -- 2.25.1 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".