static int get_requested_picture
(
libavsmash_video_decode_handler_t *vdhp,
AVFrame *picture,
uint32_t sample_number
)
{
#define MAX_ERROR_COUNT 3 /* arbitrary */
codec_configuration_t *config = &vdhp->config;
uint32_t config_index;
if( sample_number < vdhp->first_valid_frame_number || vdhp->sample_count == 1 )
{
/* Get the index of the decoder configuration. */
lsmash_sample_t sample;
uint32_t decoding_sample_number = get_decoding_sample_number( vdhp->order_converter, vdhp->first_valid_frame_number );
if( lsmash_get_sample_info_from_media_timeline( vdhp->root, vdhp->track_id, decoding_sample_number, &sample ) < 0 )
goto video_fail;
config_index = sample.index;
/* Copy the first valid video frame data. */
av_frame_unref( picture );
if( av_frame_ref( picture, vdhp->first_valid_frame ) < 0 )
goto video_fail;
/* Force seeking at the next access for valid video frame. */
vdhp->last_sample_number = vdhp->sample_count + 1;
goto return_frame;
}
uint32_t start_number; /* number of sample, for normal decoding, where decoding starts excluding decoding delay */
uint32_t rap_number; /* number of sample, for seeking, where decoding starts excluding decoding delay */
int seek_mode = vdhp->seek_mode;
int roll_recovery = 0;
if( sample_number > vdhp->last_sample_number
&& sample_number <= vdhp->last_sample_number + vdhp->forward_seek_threshold )
{
start_number = vdhp->last_sample_number + 1 + config->delay_count;
rap_number = vdhp->last_rap_number;
}
else
{
roll_recovery = find_random_accessible_point( vdhp, sample_number, 0, &rap_number );
if( rap_number == vdhp->last_rap_number && sample_number > vdhp->last_sample_number )
{
roll_recovery = 0;
start_number = vdhp->last_sample_number + 1 + config->delay_count;
}
else
{
/* Require starting to decode from random accessible sample. */
vdhp->last_rap_number = rap_number;
start_number = seek_video( vdhp, picture, sample_number, rap_number, roll_recovery || seek_mode != SEEK_MODE_NORMAL );
}
}
/* Get the desired picture. */
int error_count = 0;
while( start_number == 0 /* Failed to seek. */
|| config->update_pending /* Need to update the decoder configuration to decode pictures. */
|| get_picture( vdhp, picture, start_number, sample_number + config->delay_count ) < 0 )
{
if( config->update_pending )
{
roll_recovery = find_random_accessible_point( vdhp, sample_number, 0, &rap_number );
vdhp->last_rap_number = rap_number;
}
else
{
/* Failed to get the desired picture. */
if( config->error || seek_mode == SEEK_MODE_AGGRESSIVE )
goto video_fail;
if( ++error_count > MAX_ERROR_COUNT || rap_number <= 1 )
{
if( seek_mode == SEEK_MODE_UNSAFE )
goto video_fail;
/* Retry to decode from the same random accessible sample with error ignorance. */
seek_mode = SEEK_MODE_AGGRESSIVE;
}
else
{
/* Retry to decode from more past random accessible sample. */
roll_recovery = find_random_accessible_point( vdhp, sample_number, rap_number - 1, &rap_number );
if( vdhp->last_rap_number == rap_number )
goto video_fail;
vdhp->last_rap_number = rap_number;
}
}
start_number = seek_video( vdhp, picture, sample_number, rap_number, roll_recovery || seek_mode != SEEK_MODE_NORMAL );
}
vdhp->last_sample_number = sample_number;
config_index = config->index;
return_frame:;
/* Don't exceed the maximum presentation size specified for each sequence. */
extended_summary_t *extended = &config->entries[ config_index - 1 ].extended;
if( config->ctx->width > extended->width )
config->ctx->width = extended->width;
if( config->ctx->height > extended->height )
config->ctx->height = extended->height;
return 0;
video_fail:
/* fatal error of decoding */
lw_log_show( &config->lh, LW_LOG_WARNING, "Couldn't read video frame." );
return -1;
#undef MAX_ERROR_COUNT
}
static int get_requested_picture
(
lwlibav_video_decode_handler_t *vdhp,
AVFrame *picture,
uint32_t frame_number
)
{
#define MAX_ERROR_COUNT 3 /* arbitrary */
if( frame_number > vdhp->frame_count )
frame_number = vdhp->frame_count;
uint32_t extradata_index;
if( frame_number == vdhp->last_frame_number
|| frame_number == vdhp->last_frame_number + vdhp->last_half_offset )
{
/* The last frame is the requested frame. */
if( copy_last_frame( vdhp, picture ) < 0 )
goto video_fail;
extradata_index = vdhp->frame_list[frame_number].extradata_index;
goto return_frame;
}
if( frame_number < vdhp->first_valid_frame_number || vdhp->frame_count == 1 )
{
/* Copy the first valid video frame data. */
av_frame_unref( picture );
if( av_frame_ref( picture, vdhp->first_valid_frame ) < 0 )
goto video_fail;
/* Force seeking at the next access for valid video frame. */
vdhp->last_frame_number = vdhp->frame_count + 1;
vdhp->last_frame_buffer = picture;
/* Return the first valid video frame. */
extradata_index = vdhp->frame_list[ vdhp->first_valid_frame_number ].extradata_index;
goto return_frame;
}
uint32_t start_number; /* number of sample, for normal decoding, where decoding starts excluding decoding delay */
uint32_t rap_number; /* number of sample, for seeking, where decoding starts excluding decoding delay */
uint32_t last_frame_number = vdhp->last_frame_number + vdhp->last_half_offset;
int seek_mode = vdhp->seek_mode;
int64_t rap_pos = INT64_MIN;
if( frame_number > last_frame_number
&& frame_number <= last_frame_number + vdhp->forward_seek_threshold )
{
start_number = last_frame_number + 1 + vdhp->exh.delay_count;
rap_number = vdhp->last_rap_number;
}
else
{
lwlibav_find_random_accessible_point( vdhp, frame_number, 0, &rap_number );
if( rap_number == vdhp->last_rap_number && frame_number > last_frame_number )
start_number = last_frame_number + 1 + vdhp->exh.delay_count;
else
{
/* Require starting to decode from random accessible sample. */
rap_pos = lwlibav_get_random_accessible_point_position( vdhp, rap_number );
vdhp->last_rap_number = rap_number;
start_number = seek_video( vdhp, picture, frame_number, rap_number, rap_pos, seek_mode != SEEK_MODE_NORMAL );
}
}
/* Get requested picture. */
int error_count = 0;
while( start_number == 0
|| get_picture( vdhp, picture, start_number, frame_number + vdhp->exh.delay_count, rap_number ) < 0 )
{
/* Failed to get desired picture. */
if( vdhp->error || seek_mode == SEEK_MODE_AGGRESSIVE )
goto video_fail;
if( ++error_count > MAX_ERROR_COUNT || rap_number <= 1 )
{
if( seek_mode == SEEK_MODE_UNSAFE )
goto video_fail;
/* Retry to decode from the same random accessible sample with error ignorance. */
seek_mode = SEEK_MODE_AGGRESSIVE;
}
else
{
/* Retry to decode from more past random accessible sample. */
lwlibav_find_random_accessible_point( vdhp, frame_number, rap_number - 1, &rap_number );
rap_pos = lwlibav_get_random_accessible_point_position( vdhp, rap_number );
vdhp->last_rap_number = rap_number;
}
start_number = seek_video( vdhp, picture, frame_number, rap_number, rap_pos, seek_mode != SEEK_MODE_NORMAL );
}
vdhp->last_frame_number = frame_number;
vdhp->last_frame_buffer = picture;
if( vdhp->last_half_frame == UINT32_MAX )
{
/* The second field was requested in this time.
* Shift the last frame number to the first field number. */
vdhp->last_frame_number -= 1;
vdhp->last_half_frame = 1;
}
extradata_index = vdhp->frame_list[frame_number].extradata_index;
return_frame:;
/* Don't exceed the maximum presentation size specified for each sequence. */
lwlibav_extradata_t *entry = &vdhp->exh.entries[extradata_index];
if( vdhp->ctx->width > entry->width )
vdhp->ctx->width = entry->width;
if( vdhp->ctx->height > entry->height )
vdhp->ctx->height = entry->height;
return 0;
video_fail:
/* fatal error of decoding */
if( vdhp->lh.show_log )
vdhp->lh.show_log( &vdhp->lh, LW_LOG_ERROR, "Couldn't get the requested video frame." );
return -1;
#undef MAX_ERROR_COUNT
}
