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Improved (I hope) A/V sync. mpegplayer now takes account of the difference in the initial audio and video PTS values, and constantly adjusts the av delay to compensate for drift between the audio PTS and the actual duration of the played audio.

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@12930 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Dave Chapman 2007-03-26 19:37:48 +00:00
parent 138baaa669
commit 704b793787
1 changed files with 33 additions and 0 deletions
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33
apps/plugins/mpegplayer/mpegplayer.c
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@ -178,6 +178,8 @@ typedef struct
size_t guard_bytes; /* Number of bytes in guardbuf used */
size_t buffer_remaining; /* How much data is left in the buffer */
uint32_t first_pts;
uint32_t curr_pts;
int id;
} Stream;
@ -464,6 +466,12 @@ static void get_next_data( Stream* str )
pts = (((header[9] >> 1) << 30) |
(header[10] << 22) | ((header[11] >> 1) << 15) |
(header[12] << 7) | (header[13] >> 1));
if (str->first_pts==0)
str->first_pts = pts;
str->curr_pts = pts;
dts = (!(header[7] & 0x40) ? pts :
((uint32_t)(((header[14] >> 1) << 30) |
(header[15] << 22) |
@ -558,6 +566,7 @@ static volatile int16_t* pcmbuf_head IBSS_ATTR;
static volatile int16_t* pcmbuf_tail IBSS_ATTR;
static volatile uint32_t samplesplayed IBSS_ATTR;
static volatile int delay IBSS_ATTR;
static void init_pcmbuf(void)
{
@ -599,6 +608,10 @@ static void audio_thread(void)
size_t len;
int file_end = 0; /* A count of the errors in each frame */
int framelength;
int found_avdelay = 0;
int avdelay = 0; /* Number of audio samples difference between first audio and video PTS values. */
int64_t apts_samples;
uint32_t samplesdecoded = 0;
/* We need this here to init the EMAC for Coldfire targets */
mad_synth_init(&synth);
@ -609,6 +622,14 @@ static void audio_thread(void)
for (;;) {
button_loop();
if (!found_avdelay) {
if ((audio_str.first_pts != 0) && (video_str.first_pts != 0)) {
avdelay = ((audio_str.first_pts - video_str.first_pts)*44100)/90000;
found_avdelay = 1;
DEBUGF("First Audio PTS = %lu, First Video PTS=%lu, A-V=%d samples\n",audio_str.first_pts,video_str.first_pts,avdelay);
}
}
if (audiostatus == PLEASE_STOP) {
goto done;
}
@ -620,6 +641,7 @@ static void audio_thread(void)
while (pcmbuf_len > 0) { rb->sleep(HZ/10); }
goto done;
}
len = audio_str.curr_packet_end - audio_str.curr_packet;
if (n + len > mpa_buffer_size) {
rb->splash( 30, "Audio buffer overflow" );
@ -689,6 +711,14 @@ static void audio_thread(void)
#endif
framelength = synth.pcm.length;
samplesdecoded += framelength;
if (found_avdelay) {
apts_samples = (audio_str.curr_pts-audio_str.first_pts);
apts_samples *= 44100;
apts_samples /= 90000;
delay=(int)(avdelay+apts_samples-samplesdecoded);
}
if (framelength > 0) {
/* Leave at least 32KB free (this will be the currently playing chunk) */
@ -863,6 +893,8 @@ static void video_thread(void)
/* Convert eta (in 27MHz ticks) into audio samples */
eta2 =(eta * 44100) / 27000000;
eta2 -= delay;
s = samplesplayed - (rb->pcm_get_bytes_waiting() >> 2);
if (settings.limitfps) {
if (eta2 > s) {
@ -1042,6 +1074,7 @@ enum plugin_status plugin_start(struct plugin_api* api, void* parameter)
file_remaining -= disk_buf_len;
video_str.guard_bytes = audio_str.guard_bytes = 0;
video_str.first_pts = audio_str.first_pts = 0;
video_str.prev_packet = disk_buf;
audio_str.prev_packet = disk_buf;
video_str.buffer_remaining = disk_buf_len;