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| author | Michael Niedermayer <michaelni@gmx.at> | 2015-05-25 12:43:51 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michaelni@gmx.at> | 2015-05-25 12:43:51 +0200 |
| commit | 73f71799242e9f1258ff80b0afcafaf50aed23ca (patch) | |
| tree | cf079b2f5ced17fc175d642c14f792f26c2b199b /libavformat/mpegenc.c | |
| parent | 2ce6e419113f8276f417a9a8b50122c5467d9bc5 (diff) | |
| download | ffmpeg-73f71799242e9f1258ff80b0afcafaf50aed23ca.tar.gz | |
avformat/mpegenc: Do not use floats for vcd_padding_bitrate
This reduces the risk for rounding differences.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Diffstat (limited to 'libavformat/mpegenc.c')
| -rw-r--r-- | libavformat/mpegenc.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/libavformat/mpegenc.c b/libavformat/mpegenc.c index af40fd3b31..4984d57435 100644 --- a/libavformat/mpegenc.c +++ b/libavformat/mpegenc.c @@ -77,7 +77,7 @@ typedef struct MpegMuxContext { int is_dvd; int64_t last_scr; /* current system clock */ - double vcd_padding_bitrate; // FIXME floats + int64_t vcd_padding_bitrate_num; int64_t vcd_padding_bytes_written; int preload; @@ -324,7 +324,7 @@ static av_cold int mpeg_mux_init(AVFormatContext *ctx) ctx->max_delay = 0.7*AV_TIME_BASE; s->vcd_padding_bytes_written = 0; - s->vcd_padding_bitrate = 0; + s->vcd_padding_bitrate_num = 0; s->audio_bound = 0; s->video_bound = 0; @@ -456,7 +456,7 @@ static av_cold int mpeg_mux_init(AVFormatContext *ctx) } if (s->is_vcd) { - double overhead_rate; + int64_t overhead_rate; /* The VCD standard mandates that the mux_rate field is 3528 * (see standard p. IV-6). @@ -476,12 +476,12 @@ static av_cold int mpeg_mux_init(AVFormatContext *ctx) /* Add the header overhead to the data rate. * 2279 data bytes per audio pack, 2294 data bytes per video pack */ - overhead_rate = ((audio_bitrate / 8.0) / 2279) * (2324 - 2279); - overhead_rate += ((video_bitrate / 8.0) / 2294) * (2324 - 2294); - overhead_rate *= 8; + overhead_rate = audio_bitrate * 2294LL * (2324 - 2279); + overhead_rate += video_bitrate * 2279LL * (2324 - 2294); /* Add padding so that the full bitrate is 2324*75 bytes/sec */ - s->vcd_padding_bitrate = 2324 * 75 * 8 - (bitrate + overhead_rate); + s->vcd_padding_bitrate_num = (2324LL * 75 * 8 - bitrate) * 2279 * 2294 - overhead_rate; +#define VCD_PADDING_BITRATE_DEN (2279 * 2294) } if (s->is_vcd || s->is_mpeg2) @@ -534,12 +534,12 @@ static int get_vcd_padding_size(AVFormatContext *ctx, int64_t pts) MpegMuxContext *s = ctx->priv_data; int pad_bytes = 0; - if (s->vcd_padding_bitrate > 0 && pts != AV_NOPTS_VALUE) { + if (s->vcd_padding_bitrate_num > 0 && pts != AV_NOPTS_VALUE) { int64_t full_pad_bytes; // FIXME: this is wrong full_pad_bytes = - (int64_t)((s->vcd_padding_bitrate * (pts / 90000.0)) / 8.0); + av_rescale(s->vcd_padding_bitrate_num, pts, 90000LL * 8 * VCD_PADDING_BITRATE_DEN); pad_bytes = (int)(full_pad_bytes - s->vcd_padding_bytes_written); if (pad_bytes < 0) |