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suppress PTS in packets when not needed (slightly smaller files), fixed PTS generation in some cases, added provision for DTS generation, slightly better SCR generation (initial patch by Michel Bardiaux)

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Originally committed as revision 2585 to svn://svn.ffmpeg.org/ffmpeg/trunk
pull/126/head
Michel Bardiaux 21 years ago committed by Fabrice Bellard
parent 8a56ac7b89
commit 27a206e031
1 changed files with 103 additions and 31 deletions
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  1. 134
      libavformat/mpeg.c

134
libavformat/mpeg.c
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@ -19,7 +19,6 @@
#include "avformat.h" #include "avformat.h"
#define MAX_PAYLOAD_SIZE 4096 #define MAX_PAYLOAD_SIZE 4096
#define NB_STREAMS 2
//#define DEBUG_SEEK //#define DEBUG_SEEK
typedef struct { typedef struct {
@ -29,6 +28,7 @@ typedef struct {
int max_buffer_size; /* in bytes */ int max_buffer_size; /* in bytes */
int packet_number; int packet_number;
int64_t start_pts; int64_t start_pts;
int64_t start_dts;
} StreamInfo; } StreamInfo;
typedef struct { typedef struct {
@ -43,6 +43,9 @@ typedef struct {
int video_bound; int video_bound;
int is_mpeg2; int is_mpeg2;
int is_vcd; int is_vcd;
int scr_stream_index; /* stream from which the system clock is
computed (VBR case) */
int64_t last_scr; /* current system clock */
} MpegMuxContext; } MpegMuxContext;
#define PACK_START_CODE ((unsigned int)0x000001ba) #define PACK_START_CODE ((unsigned int)0x000001ba)
@ -181,11 +184,14 @@ static int mpeg_mux_init(AVFormatContext *ctx)
/* startcode(4) + length(2) + flags(1) */ /* startcode(4) + length(2) + flags(1) */
s->packet_data_max_size = s->packet_size - 7; s->packet_data_max_size = s->packet_size - 7;
if (s->is_mpeg2)
s->packet_data_max_size -= 2;
s->audio_bound = 0; s->audio_bound = 0;
s->video_bound = 0; s->video_bound = 0;
mpa_id = AUDIO_ID; mpa_id = AUDIO_ID;
ac3_id = 0x80; ac3_id = 0x80;
mpv_id = VIDEO_ID; mpv_id = VIDEO_ID;
s->scr_stream_index = -1;
for(i=0;i<ctx->nb_streams;i++) { for(i=0;i<ctx->nb_streams;i++) {
st = ctx->streams[i]; st = ctx->streams[i];
stream = av_mallocz(sizeof(StreamInfo)); stream = av_mallocz(sizeof(StreamInfo));
@ -203,6 +209,9 @@ static int mpeg_mux_init(AVFormatContext *ctx)
s->audio_bound++; s->audio_bound++;
break; break;
case CODEC_TYPE_VIDEO: case CODEC_TYPE_VIDEO:
/* by default, video is used for the SCR computation */
if (s->scr_stream_index == -1)
s->scr_stream_index = i;
stream->id = mpv_id++; stream->id = mpv_id++;
stream->max_buffer_size = 46 * 1024; stream->max_buffer_size = 46 * 1024;
s->video_bound++; s->video_bound++;
@ -211,6 +220,9 @@ static int mpeg_mux_init(AVFormatContext *ctx)
av_abort(); av_abort();
} }
} }
/* if no SCR, use first stream (audio) */
if (s->scr_stream_index == -1)
s->scr_stream_index = 0;
/* we increase slightly the bitrate to take into account the /* we increase slightly the bitrate to take into account the
headers. XXX: compute it exactly */ headers. XXX: compute it exactly */
@ -245,8 +257,10 @@ static int mpeg_mux_init(AVFormatContext *ctx)
stream = ctx->streams[i]->priv_data; stream = ctx->streams[i]->priv_data;
stream->buffer_ptr = 0; stream->buffer_ptr = 0;
stream->packet_number = 0; stream->packet_number = 0;
stream->start_pts = -1; stream->start_pts = AV_NOPTS_VALUE;
stream->start_dts = AV_NOPTS_VALUE;
} }
s->last_scr = 0;
return 0; return 0;
fail: fail:
for(i=0;i<ctx->nb_streams;i++) { for(i=0;i<ctx->nb_streams;i++) {
@ -255,28 +269,37 @@ static int mpeg_mux_init(AVFormatContext *ctx)
return -ENOMEM; return -ENOMEM;
} }
static inline void put_timestamp(ByteIOContext *pb, int id, int64_t timestamp)
{
put_byte(pb,
(id << 4) |
(((timestamp >> 30) & 0x07) << 1) |
1);
put_be16(pb, (uint16_t)((((timestamp >> 15) & 0x7fff) << 1) | 1));
put_be16(pb, (uint16_t)((((timestamp) & 0x7fff) << 1) | 1));
}
/* flush the packet on stream stream_index */ /* flush the packet on stream stream_index */
static void flush_packet(AVFormatContext *ctx, int stream_index) static void flush_packet(AVFormatContext *ctx, int stream_index,
int64_t pts, int64_t dts, int64_t scr)
{ {
MpegMuxContext *s = ctx->priv_data; MpegMuxContext *s = ctx->priv_data;
StreamInfo *stream = ctx->streams[stream_index]->priv_data; StreamInfo *stream = ctx->streams[stream_index]->priv_data;
uint8_t *buf_ptr; uint8_t *buf_ptr;
int size, payload_size, startcode, id, len, stuffing_size, i, header_len; int size, payload_size, startcode, id, len, stuffing_size, i, header_len;
int64_t timestamp;
uint8_t buffer[128]; uint8_t buffer[128];
id = stream->id; id = stream->id;
timestamp = stream->start_pts;
#if 0 #if 0
printf("packet ID=%2x PTS=%0.3f\n", printf("packet ID=%2x PTS=%0.3f\n",
id, timestamp / 90000.0); id, pts / 90000.0);
#endif #endif
buf_ptr = buffer; buf_ptr = buffer;
if (((s->packet_number % s->pack_header_freq) == 0)) { if (((s->packet_number % s->pack_header_freq) == 0)) {
/* output pack and systems header if needed */ /* output pack and systems header if needed */
size = put_pack_header(ctx, buf_ptr, timestamp); size = put_pack_header(ctx, buf_ptr, scr);
buf_ptr += size; buf_ptr += size;
if ((s->packet_number % s->system_header_freq) == 0) { if ((s->packet_number % s->system_header_freq) == 0) {
size = put_system_header(ctx, buf_ptr); size = put_system_header(ctx, buf_ptr);
@ -288,10 +311,20 @@ static void flush_packet(AVFormatContext *ctx, int stream_index)
/* packet header */ /* packet header */
if (s->is_mpeg2) { if (s->is_mpeg2) {
header_len = 8; header_len = 3;
} else { } else {
header_len = 5; header_len = 0;
} }
if (pts != AV_NOPTS_VALUE) {
if (dts != AV_NOPTS_VALUE)
header_len += 5 + 5;
else
header_len += 5;
} else {
if (!s->is_mpeg2)
header_len++;
}
payload_size = s->packet_size - (size + 6 + header_len); payload_size = s->packet_size - (size + 6 + header_len);
if (id < 0xc0) { if (id < 0xc0) {
startcode = PRIVATE_STREAM_1; startcode = PRIVATE_STREAM_1;
@ -312,15 +345,34 @@ static void flush_packet(AVFormatContext *ctx, int stream_index)
if (s->is_mpeg2) { if (s->is_mpeg2) {
put_byte(&ctx->pb, 0x80); /* mpeg2 id */ put_byte(&ctx->pb, 0x80); /* mpeg2 id */
put_byte(&ctx->pb, 0x80); /* flags */
put_byte(&ctx->pb, 0x05); /* header len (only pts is included) */ if (pts != AV_NOPTS_VALUE) {
if (dts != AV_NOPTS_VALUE) {
put_byte(&ctx->pb, 0xc0); /* flags */
put_byte(&ctx->pb, header_len - 3);
put_timestamp(&ctx->pb, 0x03, pts);
put_timestamp(&ctx->pb, 0x01, dts);
} else {
put_byte(&ctx->pb, 0x80); /* flags */
put_byte(&ctx->pb, header_len - 3);
put_timestamp(&ctx->pb, 0x02, pts);
}
} else {
put_byte(&ctx->pb, 0x00); /* flags */
put_byte(&ctx->pb, header_len - 3);
}
} else {
if (pts != AV_NOPTS_VALUE) {
if (dts != AV_NOPTS_VALUE) {
put_timestamp(&ctx->pb, 0x03, pts);
put_timestamp(&ctx->pb, 0x01, dts);
} else {
put_timestamp(&ctx->pb, 0x02, pts);
}
} else {
put_byte(&ctx->pb, 0x0f);
}
} }
put_byte(&ctx->pb,
(0x02 << 4) |
(((timestamp >> 30) & 0x07) << 1) |
1);
put_be16(&ctx->pb, (uint16_t)((((timestamp >> 15) & 0x7fff) << 1) | 1));
put_be16(&ctx->pb, (uint16_t)((((timestamp) & 0x7fff) << 1) | 1));
if (startcode == PRIVATE_STREAM_1) { if (startcode == PRIVATE_STREAM_1) {
put_byte(&ctx->pb, id); put_byte(&ctx->pb, id);
@ -345,7 +397,6 @@ static void flush_packet(AVFormatContext *ctx, int stream_index)
s->packet_number++; s->packet_number++;
stream->packet_number++; stream->packet_number++;
stream->start_pts = -1;
} }
static int mpeg_mux_write_packet(AVFormatContext *ctx, int stream_index, static int mpeg_mux_write_packet(AVFormatContext *ctx, int stream_index,
@ -354,13 +405,28 @@ static int mpeg_mux_write_packet(AVFormatContext *ctx, int stream_index,
MpegMuxContext *s = ctx->priv_data; MpegMuxContext *s = ctx->priv_data;
AVStream *st = ctx->streams[stream_index]; AVStream *st = ctx->streams[stream_index];
StreamInfo *stream = st->priv_data; StreamInfo *stream = st->priv_data;
int64_t dts;
int len; int len;
/* XXX: system clock should be computed precisely, especially for
CBR case. The current mode gives at least something coherent */
if (stream_index == s->scr_stream_index)
s->last_scr = pts;
#if 0
printf("%d: pts=%0.3f scr=%0.3f\n",
stream_index, pts / 90000.0, s->last_scr / 90000.0);
#endif
/* XXX: currently no way to pass dts, will change soon */
dts = AV_NOPTS_VALUE;
/* we assume here that pts != AV_NOPTS_VALUE */
if (stream->start_pts == AV_NOPTS_VALUE) {
stream->start_pts = pts;
stream->start_dts = dts;
}
while (size > 0) { while (size > 0) {
/* set pts */
if (stream->start_pts == -1) {
stream->start_pts = pts;
}
len = s->packet_data_max_size - stream->buffer_ptr; len = s->packet_data_max_size - stream->buffer_ptr;
if (len > size) if (len > size)
len = size; len = size;
@ -370,9 +436,12 @@ static int mpeg_mux_write_packet(AVFormatContext *ctx, int stream_index,
size -= len; size -= len;
while (stream->buffer_ptr >= s->packet_data_max_size) { while (stream->buffer_ptr >= s->packet_data_max_size) {
/* output the packet */ /* output the packet */
if (stream->start_pts == -1) flush_packet(ctx, stream_index,
stream->start_pts = pts; stream->start_pts, stream->start_dts, s->last_scr);
flush_packet(ctx, stream_index); /* Make sure only the FIRST pes packet for this frame has
a timestamp */
stream->start_pts = AV_NOPTS_VALUE;
stream->start_dts = AV_NOPTS_VALUE;
} }
} }
return 0; return 0;
@ -380,14 +449,15 @@ static int mpeg_mux_write_packet(AVFormatContext *ctx, int stream_index,
static int mpeg_mux_end(AVFormatContext *ctx) static int mpeg_mux_end(AVFormatContext *ctx)
{ {
MpegMuxContext *s = ctx->priv_data;
StreamInfo *stream; StreamInfo *stream;
int i; int i;
/* flush each packet */ /* flush each packet */
for(i=0;i<ctx->nb_streams;i++) { for(i=0;i<ctx->nb_streams;i++) {
stream = ctx->streams[i]->priv_data; stream = ctx->streams[i]->priv_data;
if (stream->buffer_ptr > 0) { while (stream->buffer_ptr > 0) {
flush_packet(ctx, i); flush_packet(ctx, i, AV_NOPTS_VALUE, AV_NOPTS_VALUE, s->last_scr);
} }
} }
@ -676,7 +746,7 @@ static int mpegps_read_packet(AVFormatContext *s,
len = mpegps_read_pes_header(s, NULL, &startcode, &pts, &dts, 1); len = mpegps_read_pes_header(s, NULL, &startcode, &pts, &dts, 1);
if (len < 0) if (len < 0)
return len; return len;
/* now find stream */ /* now find stream */
for(i=0;i<s->nb_streams;i++) { for(i=0;i<s->nb_streams;i++) {
st = s->streams[i]; st = s->streams[i];
@ -728,12 +798,14 @@ static int mpegps_read_packet(AVFormatContext *s,
st->codec.bit_rate = st->codec.channels * st->codec.sample_rate * 2; st->codec.bit_rate = st->codec.channels * st->codec.sample_rate * 2;
} }
av_new_packet(pkt, len); av_new_packet(pkt, len);
//printf("\nRead Packet ID: %x PTS: %f Size: %d", startcode,
// (float)pts/90000, len);
get_buffer(&s->pb, pkt->data, pkt->size); get_buffer(&s->pb, pkt->data, pkt->size);
pkt->pts = pts; pkt->pts = pts;
pkt->dts = dts; pkt->dts = dts;
pkt->stream_index = st->index; pkt->stream_index = st->index;
#if 0
printf("%d: pts=%0.3f dts=%0.3f\n",
pkt->stream_index, pkt->pts / 90000.0, pkt->dts / 90000.0);
#endif
return 0; return 0;
} }

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