diff options
author | Rostislav Pehlivanov <rpehlivanov@obe.tv> | 2016-04-06 13:51:24 +0300 |
---|---|---|
committer | James Darnley <jdarnley@obe.tv> | 2018-01-31 19:29:45 +0300 |
commit | 61a4ee8ab482925cb419133cab42e4c4ef6a3f07 (patch) | |
tree | 9a0a887360fcd56362c9eafd706e2067d4ef3d8a /libavcodec/vc2enc.c | |
parent | fe1e6c06d03432c3e9208f019533c1d701f485d0 (diff) |
avcodec/vc2enc: prevent bitrate overshoots
The rounding caused by the size scaler wasn't compensated for and the
slice sizes grew beyond what is allowed per frame.
Signed-off-by: Rostislav Pehlivanov <rpehlivanov@obe.tv>
Diffstat (limited to 'libavcodec/vc2enc.c')
-rw-r--r-- | libavcodec/vc2enc.c | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/libavcodec/vc2enc.c b/libavcodec/vc2enc.c index 2f08441d55..b7adcd3d36 100644 --- a/libavcodec/vc2enc.c +++ b/libavcodec/vc2enc.c @@ -164,6 +164,7 @@ typedef struct VC2EncContext { int chroma_y_shift; /* Rate control stuff */ + int frame_max_bytes; int slice_max_bytes; int slice_min_bytes; int q_ceil; @@ -715,7 +716,7 @@ static int calc_slice_sizes(VC2EncContext *s) for (i = 0; i < s->num_x*s->num_y; i++) { SliceArgs *args = &enc_args[i]; - bytes_left += s->slice_max_bytes - args->bytes; + bytes_left += args->bytes; for (j = 0; j < slice_redist_range; j++) { if (args->bytes > bytes_top[j]) { bytes_top[j] = args->bytes; @@ -725,8 +726,10 @@ static int calc_slice_sizes(VC2EncContext *s) } } + bytes_left = s->frame_max_bytes - bytes_left; + /* Second pass - distribute leftover bytes */ - while (1) { + while (bytes_left > 0) { int distributed = 0; for (i = 0; i < slice_redist_range; i++) { SliceArgs *args; @@ -994,13 +997,13 @@ static av_cold int vc2_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame, int *got_packet) { int ret = 0; - int sig_size = 256; + int slice_ceil, sig_size = 256; VC2EncContext *s = avctx->priv_data; const int bitexact = avctx->flags & AV_CODEC_FLAG_BITEXACT; const char *aux_data = bitexact ? "Lavc" : LIBAVCODEC_IDENT; const int aux_data_size = bitexact ? sizeof("Lavc") : sizeof(LIBAVCODEC_IDENT); const int header_size = 100 + aux_data_size; - int64_t max_frame_bytes, r_bitrate = avctx->bit_rate >> (s->interlaced); + int64_t r_bitrate = avctx->bit_rate >> (s->interlaced); s->avctx = avctx; s->size_scaler = 2; @@ -1009,18 +1012,21 @@ static av_cold int vc2_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, s->next_parse_offset = 0; /* Rate control */ - max_frame_bytes = (av_rescale(r_bitrate, s->avctx->time_base.num, - s->avctx->time_base.den) >> 3) - header_size; - s->slice_max_bytes = av_rescale(max_frame_bytes, 1, s->num_x*s->num_y); + s->frame_max_bytes = (av_rescale(r_bitrate, s->avctx->time_base.num, + s->avctx->time_base.den) >> 3) - header_size; + s->slice_max_bytes = slice_ceil = av_rescale(s->frame_max_bytes, 1, s->num_x*s->num_y); /* Find an appropriate size scaler */ while (sig_size > 255) { int r_size = SSIZE_ROUND(s->slice_max_bytes); + if (r_size > slice_ceil) { + s->slice_max_bytes -= r_size - slice_ceil; + r_size = SSIZE_ROUND(s->slice_max_bytes); + } sig_size = r_size/s->size_scaler; /* Signalled slize size */ s->size_scaler <<= 1; } - s->slice_max_bytes = SSIZE_ROUND(s->slice_max_bytes); s->slice_min_bytes = s->slice_max_bytes - s->slice_max_bytes*(s->tolerance/100.0f); ret = encode_frame(s, avpkt, frame, aux_data, header_size, s->interlaced); |