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Rework m4a seek/resume code. Seek/resume does now also work properly with files having sample_to_chunk of 1 or 2.

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@29178 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Andree Buschmann 2011-01-31 21:54:50 +00:00
parent 02dce4500d
commit 411023c6be
2 changed files with 74 additions and 86 deletions
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138
apps/codecs/libm4a/m4a.c
View file

@ -267,57 +267,44 @@ unsigned int alac_seek(demux_res_t* demux_res, stream_t* stream,
uint32_t sound_sample_loc, uint32_t* sound_samples_done, uint32_t sound_sample_loc, uint32_t* sound_samples_done,
int* current_sample) int* current_sample)
{ {
uint32_t i; uint32_t i = 0;
uint32_t j; uint32_t tmp_var, tmp_cnt, tmp_dur;
uint32_t new_sample; uint32_t new_sample = 0; /* Holds the amount of chunks/frames. */
uint32_t new_sound_sample; uint32_t new_sound_sample = 0; /* Sums up total amount of samples. */
uint32_t new_pos; uint32_t new_pos; /* Holds the desired chunk/frame index. */
/* First check we have the appropriate metadata - we should always /* First check we have the appropriate metadata - we should always
* have it. * have it.
*/ */
if (!demux_res->num_time_to_samples || !demux_res->num_sample_byte_sizes)
if ((demux_res->num_time_to_samples==0) ||
(demux_res->num_sample_byte_sizes==0))
{ {
return 0; return 0;
} }
/* Find the destination block from time_to_sample array */ /* Find the destination block from time_to_sample array */
time_to_sample_t *tab = demux_res->time_to_sample;
i = 0; while (i < demux_res->num_time_to_samples)
new_sample = 0;
new_sound_sample = 0;
while ((i < demux_res->num_time_to_samples) &&
(new_sound_sample < sound_sample_loc))
{ {
j = (sound_sample_loc - new_sound_sample) / tmp_cnt = tab[i].sample_count;
demux_res->time_to_sample[i].sample_duration; tmp_dur = tab[i].sample_duration;
tmp_var = tmp_cnt * tmp_dur;
if (j <= demux_res->time_to_sample[i].sample_count) if (sound_sample_loc <= new_sound_sample + tmp_var)
{ {
new_sample += j; tmp_var = (sound_sample_loc - new_sound_sample);
new_sound_sample += j * new_sample += tmp_var / tmp_dur;
demux_res->time_to_sample[i].sample_duration; new_sound_sample += tmp_var;
break; break;
}
else
{
new_sound_sample += (demux_res->time_to_sample[i].sample_duration
* demux_res->time_to_sample[i].sample_count);
new_sample += demux_res->time_to_sample[i].sample_count;
i++;
} }
new_sample += tmp_cnt;
new_sound_sample += tmp_var;
++i;
} }
/* We know the new block, now calculate the file position. */ /* We know the new block, now calculate the file position. */
new_pos = get_sample_offset(demux_res, new_sample); new_pos = get_sample_offset(demux_res, new_sample);
/* We know the new file position, so let's try to seek to it */ /* We know the new file position, so let's try to seek to it */
if (stream->ci->seek_buffer(new_pos))
if (stream->ci->seek_buffer(new_pos))
{ {
*sound_samples_done = new_sound_sample; *sound_samples_done = new_sound_sample;
*current_sample = new_sample; *current_sample = new_sample;
@ -352,74 +339,69 @@ unsigned int alac_seek_raw(demux_res_t* demux_res, stream_t* stream,
uint32_t file_loc, uint32_t* sound_samples_done, uint32_t file_loc, uint32_t* sound_samples_done,
int* current_sample) int* current_sample)
{ {
uint32_t chunk_sample = 0; uint32_t chunk_sample = 0; /* Holds the chunk/frame index. */
uint32_t total_samples = 0; uint32_t total_samples = 0; /* Sums up total amount of chunks/frames. */
uint32_t new_sound_sample = 0; uint32_t new_sound_sample = 0; /* Sums up total amount of samples. */
uint32_t new_pos; uint32_t new_pos;
uint32_t chunk; uint32_t chunk;
uint32_t i; uint32_t i, tmp_dur, tmp_cnt;
if (!demux_res->num_chunk_offsets || /* There is no metadata available to perform raw seek. */
!demux_res->num_sample_to_chunks) if (!demux_res->num_chunk_offsets || !demux_res->num_sample_to_chunks)
{ {
return 0; return 0;
} }
/* Locate the chunk containing file_loc. */ /* Locate the chunk containing file_loc. */
chunk = 0;
for (i = 0; i < demux_res->num_chunk_offsets && while (chunk < demux_res->num_chunk_offsets)
file_loc > demux_res->chunk_offset[i]; i++)
{ {
} if (file_loc < demux_res->chunk_offset[chunk++])
chunk = i + 1;
new_pos = demux_res->chunk_offset[chunk - 1];
/* Get the first sample of the chunk. */
for (i = 1; i < demux_res->num_sample_to_chunks &&
chunk > demux_res->sample_to_chunk[i - 1].first_chunk; i++)
{
chunk_sample += demux_res->sample_to_chunk[i - 1].num_samples *
(demux_res->sample_to_chunk[i].first_chunk -
demux_res->sample_to_chunk[i - 1].first_chunk);
}
chunk_sample += (chunk - demux_res->sample_to_chunk[i - 1].first_chunk) *
demux_res->sample_to_chunk[i - 1].num_samples;
/* Get the position within the chunk. */
for (; chunk_sample < demux_res->num_sample_byte_sizes; chunk_sample++)
{
if (file_loc < new_pos + demux_res->sample_byte_size[chunk_sample])
{ {
break; break;
} }
}
new_pos += demux_res->sample_byte_size[chunk_sample]; new_pos = demux_res->chunk_offset[chunk-1];
/* Get the first sample of the chunk. */
i = 1;
sample_to_chunk_t *tab1 = demux_res->sample_to_chunk;
while (i < demux_res->num_sample_to_chunks)
{
if (chunk <= tab1[i].first_chunk)
{
break;
}
chunk_sample += tab1[i-1].num_samples * (tab1[i].first_chunk - tab1[i-1].first_chunk);
++i;
}
chunk_sample += (chunk - tab1[i-1].first_chunk) * tab1[i-1].num_samples;
/* Get the position within the chunk. */
while (chunk_sample < demux_res->num_sample_byte_sizes &&
file_loc >= new_pos + demux_res->sample_byte_size[chunk_sample])
{
new_pos += demux_res->sample_byte_size[chunk_sample++];
} }
/* Get sound sample offset. */ /* Get sound sample offset. */
i = 0;
for (i = 0; i < demux_res->num_time_to_samples; i++) time_to_sample_t *tab2 = demux_res->time_to_sample;
while (i < demux_res->num_time_to_samples)
{ {
if (chunk_sample < tmp_dur = tab2[i].sample_duration;
total_samples + demux_res->time_to_sample[i].sample_count) tmp_cnt = tab2[i].sample_count;
total_samples += tmp_cnt;
new_sound_sample += tmp_cnt * tmp_dur;
if (chunk_sample <= total_samples)
{ {
new_sound_sample += (chunk_sample - total_samples) * tmp_dur;
break; break;
} }
++i;
total_samples += demux_res->time_to_sample[i].sample_count;
new_sound_sample += demux_res->time_to_sample[i].sample_count
* demux_res->time_to_sample[i].sample_duration;
} }
new_sound_sample += (chunk_sample - total_samples)
* demux_res->time_to_sample[i].sample_duration;
/* Go to the new file position. */ /* Go to the new file position. */
if (stream->ci->seek_buffer(new_pos)) if (stream->ci->seek_buffer(new_pos))
{ {
*sound_samples_done = new_sound_sample; *sound_samples_done = new_sound_sample;

22
apps/codecs/libm4a/m4a.h
View file

@ -45,6 +45,18 @@ typedef struct {
typedef uint32_t fourcc_t; typedef uint32_t fourcc_t;
typedef struct
{
uint32_t first_chunk;
uint32_t num_samples;
} sample_to_chunk_t;
typedef struct
{
uint32_t sample_count;
uint32_t sample_duration;
} time_to_sample_t;
typedef struct typedef struct
{ {
uint16_t num_channels; uint16_t num_channels;
@ -53,19 +65,13 @@ typedef struct
fourcc_t format; fourcc_t format;
void *buf; void *buf;
struct { sample_to_chunk_t *sample_to_chunk;
uint32_t first_chunk;
uint32_t num_samples;
} *sample_to_chunk;
uint32_t num_sample_to_chunks; uint32_t num_sample_to_chunks;
uint32_t *chunk_offset; uint32_t *chunk_offset;
uint32_t num_chunk_offsets; uint32_t num_chunk_offsets;
struct { time_to_sample_t *time_to_sample;
uint32_t sample_count;
uint32_t sample_duration;
} *time_to_sample;
uint32_t num_time_to_samples; uint32_t num_time_to_samples;
uint16_t *sample_byte_size; uint16_t *sample_byte_size;