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avformat/mpegenc: Do not use floats for vcd_padding_bitrate

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This reduces the risk for rounding differences.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Michael Niedermayer 2015-05-25 12:43:51 +02:00
parent 2ce6e41911
commit 73f7179924
1 changed files with 9 additions and 9 deletions
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18
libavformat/mpegenc.c
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@ -77,7 +77,7 @@ typedef struct MpegMuxContext {
int is_dvd; int is_dvd;
int64_t last_scr; /* current system clock */ 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; int64_t vcd_padding_bytes_written;
int preload; int preload;
@ -324,7 +324,7 @@ static av_cold int mpeg_mux_init(AVFormatContext *ctx)
ctx->max_delay = 0.7*AV_TIME_BASE; ctx->max_delay = 0.7*AV_TIME_BASE;
s->vcd_padding_bytes_written = 0; s->vcd_padding_bytes_written = 0;
s->vcd_padding_bitrate = 0; s->vcd_padding_bitrate_num = 0;
s->audio_bound = 0; s->audio_bound = 0;
s->video_bound = 0; s->video_bound = 0;
@ -456,7 +456,7 @@ static av_cold int mpeg_mux_init(AVFormatContext *ctx)
} }
if (s->is_vcd) { if (s->is_vcd) {
double overhead_rate; int64_t overhead_rate;
/* The VCD standard mandates that the mux_rate field is 3528 /* The VCD standard mandates that the mux_rate field is 3528
* (see standard p. IV-6). * (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. /* Add the header overhead to the data rate.
* 2279 data bytes per audio pack, 2294 data bytes per video pack */ * 2279 data bytes per audio pack, 2294 data bytes per video pack */
overhead_rate = ((audio_bitrate / 8.0) / 2279) * (2324 - 2279); overhead_rate = audio_bitrate * 2294LL * (2324 - 2279);
overhead_rate += ((video_bitrate / 8.0) / 2294) * (2324 - 2294); overhead_rate += video_bitrate * 2279LL * (2324 - 2294);
overhead_rate *= 8;
/* Add padding so that the full bitrate is 2324*75 bytes/sec */ /* 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) 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; MpegMuxContext *s = ctx->priv_data;
int pad_bytes = 0; 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; int64_t full_pad_bytes;
// FIXME: this is wrong // FIXME: this is wrong
full_pad_bytes = 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); pad_bytes = (int)(full_pad_bytes - s->vcd_padding_bytes_written);
if (pad_bytes < 0) if (pad_bytes < 0)