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;
}
uint64_t lwlibav_audio_get_pcm_samples
(
lwlibav_audio_decode_handler_t *adhp,
lwlibav_audio_output_handler_t *aohp,
void *buf,
int64_t start,
int64_t wanted_length
)
{
if( adhp->error )
return 0;
uint32_t frame_number;
uint32_t rap_number = 0;
uint32_t past_rap_number = 0;
uint64_t output_length = 0;
enum audio_output_flag output_flags = AUDIO_OUTPUT_NO_FLAGS;
AVPacket *pkt = &adhp->packet;
AVPacket *alter_pkt = &adhp->alter_packet;
int already_gotten;
aohp->request_length = wanted_length;
if( start > 0 && start == adhp->next_pcm_sample_number )
{
frame_number = adhp->last_frame_number;
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( alter_pkt->size <= 0 )
++frame_number;
aohp->output_sample_offset = 0;
already_gotten = 0;
}
else
{
/* Seek audio stream. */
adhp->next_pcm_sample_number = 0;
adhp->last_frame_number = 0;
/* Get frame_number. */
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;
}
frame_number = find_start_audio_frame( adhp, aohp->output_sample_rate, start_frame_pos, &aohp->output_sample_offset );
retry_seek:
av_packet_unref( pkt );
/* Flush audio resampler buffers. */
if( flush_resampler_buffers( aohp->avr_ctx ) < 0 )
{
adhp->error = 1;
lw_log_show( &adhp->lh, LW_LOG_FATAL,
"Failed to flush resampler buffers.\n"
"It is recommended you reopen the file." );
return 0;
}
/* Flush audio decoder buffers. */
lwlibav_extradata_handler_t *exhp = &adhp->exh;
int extradata_index = adhp->frame_list[frame_number].extradata_index;
if( extradata_index != exhp->current_index )
{
/* Update the extradata. */
rap_number = get_audio_rap( adhp, frame_number );
assert( rap_number != 0 );
lwlibav_update_configuration( (lwlibav_decode_handler_t *)adhp, rap_number, extradata_index, 0 );
}
else
lwlibav_flush_buffers( (lwlibav_decode_handler_t *)adhp );
if( adhp->error )
return 0;
/* Seek and get a audio packet. */
rap_number = seek_audio( adhp, frame_number, past_rap_number, pkt, output_flags != AUDIO_OUTPUT_NO_FLAGS ? adhp->frame_buffer : NULL );
already_gotten = 1;
}
do
{
if( already_gotten )
{
already_gotten = 0;
make_decodable_packet( alter_pkt, pkt );
}
else if( frame_number > adhp->frame_count )
{
av_packet_unref( pkt );
if( adhp->exh.delay_count || !(output_flags & AUDIO_OUTPUT_ENOUGH) )
{
/* Null packet */
av_init_packet( pkt );
make_null_packet( pkt );
*alter_pkt = *pkt;
if( adhp->exh.delay_count )
adhp->exh.delay_count -= 1;
}
else
goto audio_out;
}
else if( alter_pkt->size <= 0 )
{
/* Getting an audio packet must be after flushing all remaining samples in resampler's FIFO buffer. */
lwlibav_get_av_frame( adhp->format, adhp->stream_index, frame_number, pkt );
make_decodable_packet( alter_pkt, pkt );
}
/* Decode and output from an audio packet. */
output_flags = AUDIO_OUTPUT_NO_FLAGS;
output_length += output_pcm_samples_from_packet( aohp, adhp->ctx, alter_pkt, adhp->frame_buffer, (uint8_t **)&buf, &output_flags );
if( output_flags & AUDIO_DECODER_DELAY )
{
if( rap_number > 1 && (output_flags & AUDIO_DECODER_ERROR) )
{
/* Retry to seek from more past audio keyframe because libavformat might have failed seek.
* This operation occurs only at the first decoding time after seek. */
past_rap_number = get_audio_rap( adhp, rap_number - 1 );
if( past_rap_number
&& past_rap_number < rap_number )
goto retry_seek;
}
++ adhp->exh.delay_count;
}
else
/* Disable seek retry. */
rap_number = 0;
if( output_flags & AUDIO_RECONFIG_FAILURE )
{
adhp->error = 1;
lw_log_show( &adhp->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;
if( output_flags & (AUDIO_DECODER_ERROR | AUDIO_DECODER_RECEIVED_PACKET) )
++frame_number;
} while( 1 );
audio_out:
adhp->next_pcm_sample_number = start + output_length;
adhp->last_frame_number = frame_number;
return output_length;
}
