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| author | Justin Ruggles <justin.ruggles@gmail.com> | 2012-02-02 16:03:41 -0500 |
|---|---|---|
| committer | Justin Ruggles <justin.ruggles@gmail.com> | 2012-02-11 12:49:22 -0500 |
| commit | 302daf580027c7151668395ff3ec706c92d2ccc6 (patch) | |
| tree | 56d7d4d8439e4ed2b692b1d34061a40b90e50c57 | |
| parent | fc9cf0b2a6a0bd3933fcef216860c594b767834e (diff) | |
| download | ffmpeg-302daf580027c7151668395ff3ec706c92d2ccc6.tar.gz | |
alacenc: calculate a new max frame size for the final small frame
Gives a better estimate of buffer requirements and a better decision of
whether or not to use verbatim mode.
| -rw-r--r-- | libavcodec/alacenc.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/libavcodec/alacenc.c b/libavcodec/alacenc.c index 9e632aeca1..bd8ab35e37 100644 --- a/libavcodec/alacenc.c +++ b/libavcodec/alacenc.c @@ -377,6 +377,11 @@ static void write_compressed_frame(AlacEncodeContext *s) } } +static av_always_inline int get_max_frame_size(int frame_size, int ch, int bps) +{ + return FFALIGN(55 + bps * ch * frame_size + 3, 8) / 8; +} + static av_cold int alac_encode_close(AVCodecContext *avctx) { AlacEncodeContext *s = avctx->priv_data; @@ -420,8 +425,9 @@ static av_cold int alac_encode_init(AVCodecContext *avctx) s->rc.k_modifier = 14; s->rc.rice_modifier = 4; - s->max_coded_frame_size = 8 + (avctx->frame_size * avctx->channels * - DEFAULT_SAMPLE_SIZE >> 3); + s->max_coded_frame_size = get_max_frame_size(avctx->frame_size, + avctx->channels, + DEFAULT_SAMPLE_SIZE); // FIXME: consider wasted_bytes s->write_sample_size = DEFAULT_SAMPLE_SIZE + avctx->channels - 1; @@ -511,8 +517,15 @@ static int alac_encode_frame(AVCodecContext *avctx, uint8_t *frame, AlacEncodeContext *s = avctx->priv_data; PutBitContext *pb = &s->pbctx; int i, out_bytes, verbatim_flag = 0; + int max_frame_size; + + if (avctx->frame_size < DEFAULT_FRAME_SIZE) + max_frame_size = get_max_frame_size(avctx->frame_size, avctx->channels, + DEFAULT_SAMPLE_SIZE); + else + max_frame_size = s->max_coded_frame_size; - if (buf_size < 2 * s->max_coded_frame_size) { + if (buf_size < 2 * max_frame_size) { av_log(avctx, AV_LOG_ERROR, "buffer size is too small\n"); return -1; } @@ -537,7 +550,7 @@ verbatim: flush_put_bits(pb); out_bytes = put_bits_count(pb) >> 3; - if (out_bytes > s->max_coded_frame_size) { + if (out_bytes > max_frame_size) { /* frame too large. use verbatim mode */ if (verbatim_flag || s->compression_level == 0) { /* still too large. must be an error. */ |