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Analysis and spec comparison

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This commit is contained in:
Mashiat Sarker Shakkhar 2011-11-05 01:24:29 +06:00 committed by Michael Niedermayer
parent 7344b75c63
commit 1f273373ec
1 changed files with 18 additions and 11 deletions
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29
libavcodec/wmalosslessdec.c
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@ -141,6 +141,9 @@ typedef struct {
DECLARE_ALIGNED(16, float, out)[WMALL_BLOCK_MAX_SIZE + WMALL_BLOCK_MAX_SIZE / 2]; ///< output buffer
} WmallChannelCtx;
/* XXX: probably we don't need subframe_config[],
WmallChannelCtx holds all the necessary data. */
/**
* @brief channel group for channel transformations
*/
@ -420,8 +423,8 @@ static int decode_subframe_length(WmallDecodeCtx *s, int offset)
if (offset == s->samples_per_frame - s->min_samples_per_subframe)
return s->min_samples_per_subframe;
len = av_log2(s->max_num_subframes - 1) + 1;
frame_len_ratio = get_bits(&s->gb, len);
len = av_log2(s->max_num_subframes - 1) + 1; // XXX: 5.3.3
frame_len_ratio = get_bits(&s->gb, len); // XXX: tile_size_ratio
subframe_len = s->min_samples_per_subframe * (frame_len_ratio + 1);
@ -455,7 +458,7 @@ static int decode_subframe_length(WmallDecodeCtx *s, int offset)
*@param s context
*@return 0 on success, < 0 in case of an error
*/
static int decode_tilehdr(WmallDecodeCtx *s)
static int decode_tilehdr(WmallDecodeCtx *s) /* XXX: decode_tile_configuration() [Table 9] */
{
uint16_t num_samples[WMALL_MAX_CHANNELS]; /**< sum of samples for all currently known subframes of a channel */
uint8_t contains_subframe[WMALL_MAX_CHANNELS]; /**< flag indicating if a channel contains the current subframe */
@ -476,8 +479,8 @@ static int decode_tilehdr(WmallDecodeCtx *s)
memset(num_samples, 0, sizeof(num_samples));
if (s->max_num_subframes == 1 || get_bits1(&s->gb))
fixed_channel_layout = 1;
if (s->max_num_subframes == 1 || get_bits1(&s->gb)) // XXX: locate in the spec
fixed_channel_layout = 1; // XXX: tile_aligned ?
/** loop until the frame data is split between the subframes */
do {
@ -491,14 +494,14 @@ static int decode_tilehdr(WmallDecodeCtx *s)
contains_subframe[c] = 1;
}
else {
contains_subframe[c] = get_bits1(&s->gb);
contains_subframe[c] = get_bits1(&s->gb); // XXX: locate in the spec
}
} else
contains_subframe[c] = 0;
}
/** get subframe length, subframe_len == 0 is not allowed */
if ((subframe_len = decode_subframe_length(s, min_channel_len)) <= 0)
if ((subframe_len = decode_subframe_length(s, min_channel_len)) <= 0) //XXX: this reads tile_size_ratio
return AVERROR_INVALIDDATA;
/** add subframes to the individual channels and find new min_channel_len */
min_channel_len += subframe_len;
@ -768,6 +771,8 @@ static int decode_subframe(WmallDecodeCtx *s)
s->seekable_tile = get_bits1(&s->gb);
if(s->seekable_tile) {
// XXX: 6.2.2 clear_codec_buffers()
s->do_arith_coding = get_bits1(&s->gb);
if(s->do_arith_coding) {
dprintf(s->avctx, "do_arith_coding == 1");
@ -786,6 +791,8 @@ static int decode_subframe(WmallDecodeCtx *s)
decode_cdlms(s);
s->movave_scaling = get_bits(&s->gb, 3);
s->quant_stepsize = get_bits(&s->gb, 8) + 1;
// XXX: 6.2.2 reset_codec()
}
rawpcm_tile = get_bits1(&s->gb);
@ -844,7 +851,7 @@ static int decode_subframe(WmallDecodeCtx *s)
av_log(s->avctx, AV_LOG_ERROR, "broken subframe\n");
return AVERROR_INVALIDDATA;
}
++s->channel[c].cur_subframe;
++s->channel[c].cur_subframe; // XXX: 6.4
}
return 0;
}
@ -873,17 +880,17 @@ static int decode_frame(WmallDecodeCtx *s)
/** get frame length */
if (s->len_prefix)
len = get_bits(gb, s->log2_frame_size);
len = get_bits(gb, s->log2_frame_size); // XXX: compressed_frame_size_bits [Table 8]
/** decode tile information */
if (decode_tilehdr(s)) {
if (decode_tilehdr(s)) { // should include decode_tile_configuration() [Table 9]
s->packet_loss = 1;
return 0;
}
/** read drc info */
if (s->dynamic_range_compression) {
s->drc_gain = get_bits(gb, 8);
s->drc_gain = get_bits(gb, 8); // XXX: drc_frame_scale_factor [Table 8]
}
/** no idea what these are for, might be the number of samples