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8svx: Fixing header size, move decoding to per call instead of the fi…
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…rst call.

The fate checksum change is due to the header size having been wrong.

Credit&Authorship for the code belongs to Justin Ruggles
Blame for bugs in this merging of the code belong to the Commiter
Commit message by Commiter
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
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@justinruggles @michaelni
justinruggles authored and michaelni committed Oct 3, 2012
1 parent 26d1c7d commit df82454
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Showing 2 changed files with 68 additions and 60 deletions.
126 changes: 67 additions & 59 deletions libavcodec/8svx.c
View file
Expand Up @@ -44,13 +44,14 @@
/** decoder context */
typedef struct EightSvxContext {
AVFrame frame;
uint8_t fib_acc[2];
const int8_t *table;

/* buffer used to store the whole audio decoded/interleaved chunk,
* which is sent with the first packet */
uint8_t *samples;
int64_t samples_size;
int samples_idx;
/* buffer used to store the whole first packet.
data is only sent as one large packet */
uint8_t *data[2];
int data_size;
int data_idx;
} EightSvxContext;

static const int8_t fibonacci[16] = { -34, -21, -13, -8, -5, -3, -2, -1, 0, 1, 2, 3, 5, 8, 13, 21 };
Expand All @@ -60,16 +61,15 @@ static const int8_t exponential[16] = { -128, -64, -32, -16, -8, -4, -2, -1, 0,

/**
* Delta decode the compressed values in src, and put the resulting
* decoded n samples in dst.
* decoded samples in dst.
*
* @param val starting value assumed by the delta sequence
* @param[in,out] state starting value. it is saved for use in the next call.
* @param table delta sequence table
* @return size in bytes of the decoded data, must be src_size*2
*/
static int delta_decode(uint8_t *dst, const uint8_t *src, int src_size,
unsigned val, const int8_t *table)
static void delta_decode(uint8_t *dst, const uint8_t *src, int src_size,
uint8_t *state, const int8_t *table)
{
uint8_t *dst0 = dst;
uint8_t val = *state;

while (src_size--) {
uint8_t d = *src++;
Expand All @@ -79,7 +79,7 @@ static int delta_decode(uint8_t *dst, const uint8_t *src, int src_size,
*dst++ = val;
}

return dst-dst0;
*state = val;
}

static void raw_decode(uint8_t *dst, const int8_t *src, int src_size)
Expand All @@ -93,72 +93,79 @@ static int eightsvx_decode_frame(AVCodecContext *avctx, void *data,
int *got_frame_ptr, AVPacket *avpkt)
{
EightSvxContext *esc = avctx->priv_data;
int n, out_data_size;
int buf_size;
int ch, ret;
int is_compr = (avctx->codec_id != AV_CODEC_ID_PCM_S8_PLANAR);
uint8_t *src;
int hdr_size = is_compr ? 2 : 0;

/* decode and interleave the first packet */
if (!esc->samples && avpkt) {
int packet_size = avpkt->size;
if (!esc->data[0] && avpkt) {
int chan_size = avpkt->size / avctx->channels - hdr_size;

if (packet_size % avctx->channels) {
if (avpkt->size % avctx->channels) {
av_log(avctx, AV_LOG_WARNING, "Packet with odd size, ignoring last byte\n");
if (packet_size < avctx->channels)
return packet_size;
packet_size -= packet_size % avctx->channels;
}
esc->samples_size = !esc->table ?
packet_size : avctx->channels + (packet_size-avctx->channels) * 2;
if (!(esc->samples = av_malloc(esc->samples_size)))
return AVERROR(ENOMEM);

/* decompress */
if (esc->table) {
const uint8_t *buf = avpkt->data;
uint8_t *dst;
int buf_size = avpkt->size;
int i, n = esc->samples_size;
if (avpkt->size < (hdr_size + 1) * avctx->channels) {
av_log(avctx, AV_LOG_ERROR, "packet size is too small\n");
return AVERROR(EINVAL);
}

if (buf_size < 2) {
av_log(avctx, AV_LOG_ERROR, "packet size is too small\n");
return AVERROR(EINVAL);
}
if (is_compr) {
esc->fib_acc[0] = avpkt->data[1] + 128;
if (avctx->channels == 2)
esc->fib_acc[1] = avpkt->data[2+chan_size+1] + 128;
}

/* the uncompressed starting value is contained in the first byte */
dst = esc->samples;
for (i = 0; i < avctx->channels; i++) {
*(dst++) = buf[0]+128;
delta_decode(dst, buf + 1, buf_size / avctx->channels - 1, (buf[0]+128)&0xFF, esc->table);
buf += buf_size / avctx->channels;
dst += n / avctx->channels - 1;
esc->data_idx = 0;
esc->data_size = chan_size;
if (!(esc->data[0] = av_malloc(chan_size)))
return AVERROR(ENOMEM);
if (avctx->channels == 2) {
if (!(esc->data[1] = av_malloc(chan_size))) {
av_freep(&esc->data[0]);
return AVERROR(ENOMEM);
}
} else {
raw_decode(esc->samples, avpkt->data, esc->samples_size);
}
memcpy(esc->data[0], &avpkt->data[hdr_size], chan_size);
if (avctx->channels == 2)
memcpy(esc->data[1], &avpkt->data[2*hdr_size+chan_size], chan_size);
}
if (!esc->data[0]) {
av_log(avctx, AV_LOG_ERROR, "unexpected empty packet\n");
return AVERROR(EINVAL);
}

/* decode next piece of data from the buffer */
buf_size = FFMIN(MAX_FRAME_SIZE, esc->data_size - esc->data_idx);
if (buf_size <= 0) {
*got_frame_ptr = 0;
return avpkt->size;
}

/* get output buffer */
av_assert1(!(esc->samples_size % avctx->channels || esc->samples_idx % avctx->channels));
esc->frame.nb_samples = FFMIN(MAX_FRAME_SIZE, esc->samples_size - esc->samples_idx) / avctx->channels;
esc->frame.nb_samples = buf_size * (is_compr + 1);
if ((ret = avctx->get_buffer(avctx, &esc->frame)) < 0) {
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
return ret;
}

for (ch = 0; ch < avctx->channels; ch++) {
if (is_compr) {
delta_decode(esc->frame.data[ch], &esc->data[ch][esc->data_idx],
buf_size, &esc->fib_acc[ch], esc->table);
} else {
raw_decode(esc->frame.data[ch], &esc->data[ch][esc->data_idx],
buf_size);
}
}

esc->data_idx += buf_size;

*got_frame_ptr = 1;
*(AVFrame *)data = esc->frame;

out_data_size = esc->frame.nb_samples;
for (ch = 0; ch<avctx->channels; ch++) {
src = esc->samples + esc->samples_idx / avctx->channels + ch * esc->samples_size / avctx->channels;
memcpy(esc->frame.data[ch], src, out_data_size);
}
out_data_size *= avctx->channels;
esc->samples_idx += out_data_size;

return esc->table ?
(avctx->frame_number == 0)*2 + out_data_size / 2 :
out_data_size;
return ((avctx->frame_number == 0)*hdr_size + buf_size)*avctx->channels;
}

static av_cold int eightsvx_decode_init(AVCodecContext *avctx)
Expand Down Expand Up @@ -191,9 +198,10 @@ static av_cold int eightsvx_decode_close(AVCodecContext *avctx)
{
EightSvxContext *esc = avctx->priv_data;

av_freep(&esc->samples);
esc->samples_size = 0;
esc->samples_idx = 0;
av_freep(&esc->data[0]);
av_freep(&esc->data[1]);
esc->data_size = 0;
esc->data_idx = 0;

return 0;
}
Expand Down
2 changes: 1 addition & 1 deletion tests/ref/fate/iff-fibonacci
View file
@@ -1 +1 @@
96a20cd1fae705cbc11eee5d6046b8e4
e968a853779bb6438339e3b8d69d8d24

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