/* This function returns the number of the next sample. */
static uint32_t seek_video
(
libavsmash_video_decode_handler_t *vdhp,
AVFrame *picture,
uint32_t composition_sample_number,
uint32_t rap_number,
int error_ignorance
)
{
/* Prepare to decode from random accessible sample. */
codec_configuration_t *config = &vdhp->config;
if( config->update_pending )
/* Update the decoder configuration. */
update_configuration( vdhp->root, vdhp->track_id, config );
else
libavsmash_flush_buffers( config );
if( config->error )
return 0;
int got_picture;
int output_ready = 0;
uint64_t rap_cts = 0;
uint32_t i;
uint32_t decoder_delay = get_decoder_delay( config->ctx );
uint32_t goal = composition_sample_number + decoder_delay;
for( i = rap_number; i < goal; i++ )
{
if( config->index == config->queue.index )
config->delay_count = MIN( decoder_delay, i - rap_number );
int ret = decode_video_sample( vdhp, picture, &got_picture, i );
if( got_picture )
{
output_ready = 1;
if( decoder_delay > config->delay_count )
{
/* Shorten the distance to the goal if we got a frame earlier than expected. */
uint32_t new_decoder_delay = config->delay_count;
goal -= decoder_delay - new_decoder_delay;
decoder_delay = new_decoder_delay;
}
}
else if( output_ready )
{
/* More input samples are required to output and the goal become more distant. */
++decoder_delay;
++goal;
}
/* Some decoders return -1 when feeding a leading sample.
* We don't consider as an error if the return value -1 is caused by a leading sample since it's not fatal at all. */
if( i == vdhp->last_rap_number )
rap_cts = picture->pts;
if( ret == -1 && (uint64_t)picture->pts >= rap_cts && !error_ignorance )
{
lw_log_show( &config->lh, LW_LOG_WARNING, "Failed to decode a video frame." );
return 0;
}
else if( ret >= 1 )
/* No decoding occurs. */
break;
}
if( config->index == config->queue.index )
config->delay_count = MIN( decoder_delay, i - rap_number );
return i;
}
uint64_t libavsmash_get_pcm_audio_samples
(
libavsmash_audio_decode_handler_t *adhp,
libavsmash_audio_output_handler_t *aohp,
void *buf,
int64_t start,
int64_t wanted_length
)
{
codec_configuration_t *config = &adhp->config;
if( config->error )
return 0;
uint32_t frame_number;
uint64_t output_length = 0;
enum audio_output_flag output_flags;
aohp->request_length = wanted_length;
if( start > 0 && start == adhp->next_pcm_sample_number )
{
frame_number = adhp->last_frame_number;
output_flags = AUDIO_OUTPUT_NO_FLAGS;
output_length += output_pcm_samples_from_buffer( aohp, adhp->frame_buffer, (uint8_t **)&buf, &output_flags );
if( output_flags & AUDIO_OUTPUT_ENOUGH )
goto audio_out;
if( adhp->packet.size <= 0 )
++frame_number;
aohp->output_sample_offset = 0;
}
else
{
/* Seek audio stream. */
if( flush_resampler_buffers( aohp->avr_ctx ) < 0 )
{
config->error = 1;
if( config->lh.show_log )
config->lh.show_log( &config->lh, LW_LOG_FATAL,
"Failed to flush resampler buffers.\n"
"It is recommended you reopen the file." );
return 0;
}
libavsmash_flush_buffers( config );
if( config->error )
return 0;
adhp->next_pcm_sample_number = 0;
adhp->last_frame_number = 0;
uint64_t start_frame_pos;
if( start >= 0 )
start_frame_pos = start;
else
{
uint64_t silence_length = -start;
put_silence_audio_samples( (int)(silence_length * aohp->output_block_align), aohp->output_bits_per_sample == 8, (uint8_t **)&buf );
output_length += silence_length;
aohp->request_length -= silence_length;
start_frame_pos = 0;
}
start_frame_pos += aohp->skip_decoded_samples;
frame_number = find_start_audio_frame( adhp, aohp->output_sample_rate, aohp->skip_decoded_samples, start_frame_pos, &aohp->output_sample_offset );
}
do
{
AVPacket *pkt = &adhp->packet;
if( frame_number > adhp->frame_count )
{
if( config->delay_count )
{
/* Null packet */
av_init_packet( pkt );
pkt->data = NULL;
pkt->size = 0;
-- config->delay_count;
}
else
goto audio_out;
}
else if( pkt->size <= 0 )
/* Getting an audio packet must be after flushing all remaining samples in resampler's FIFO buffer. */
while( get_sample( adhp->root, adhp->track_ID, frame_number, config, pkt ) == 2 )
if( config->update_pending )
/* Update the decoder configuration. */
update_configuration( adhp->root, adhp->track_ID, config );
/* Decode and output from an audio packet. */
output_flags = AUDIO_OUTPUT_NO_FLAGS;
output_length += output_pcm_samples_from_packet( aohp, config->ctx, pkt, adhp->frame_buffer, (uint8_t **)&buf, &output_flags );
if( output_flags & AUDIO_DECODER_DELAY )
++ config->delay_count;
if( output_flags & AUDIO_RECONFIG_FAILURE )
{
config->error = 1;
if( config->lh.show_log )
config->lh.show_log( &config->lh, LW_LOG_FATAL,
"Failed to reconfigure resampler.\n"
"It is recommended you reopen the file." );
goto audio_out;
}
if( output_flags & AUDIO_OUTPUT_ENOUGH )
goto audio_out;
++frame_number;
} while( 1 );
audio_out:
adhp->next_pcm_sample_number = start + output_length;
adhp->last_frame_number = frame_number;
return output_length;
}
