[FFmpeg-cvslog] r25866 - trunk/libavcodec/g722.c
mstorsjo
subversion
Fri Dec 3 22:18:45 CET 2010
Author: mstorsjo
Date: Fri Dec 3 22:18:45 2010
New Revision: 25866
Log:
g722: Add a trellis encoder
The structure is largely based on the trellis encoder in adpcm.c.
Modified:
trunk/libavcodec/g722.c
Modified: trunk/libavcodec/g722.c
==============================================================================
--- trunk/libavcodec/g722.c Fri Dec 3 22:17:23 2010 (r25865)
+++ trunk/libavcodec/g722.c Fri Dec 3 22:18:45 2010 (r25866)
@@ -43,6 +43,8 @@
#define PREV_SAMPLES_BUF_SIZE 1024
+#define FREEZE_INTERVAL 128
+
typedef struct {
int16_t prev_samples[PREV_SAMPLES_BUF_SIZE]; ///< memory of past decoded samples
int prev_samples_pos; ///< the number of values in prev_samples
@@ -61,6 +63,17 @@ typedef struct {
int16_t log_factor; ///< delayed 2-logarithmic quantizer factor
int16_t scale_factor; ///< delayed quantizer scale factor
} band[2];
+
+ struct TrellisNode {
+ struct G722Band state;
+ uint32_t ssd;
+ int path;
+ } *node_buf[2], **nodep_buf[2];
+
+ struct TrellisPath {
+ int value;
+ int prev;
+ } *paths[2];
} G722Context;
@@ -216,6 +229,29 @@ static av_cold int g722_init(AVCodecCont
if (avctx->lowres)
avctx->sample_rate /= 2;
+ if (avctx->trellis) {
+ int frontier = 1 << avctx->trellis;
+ int max_paths = frontier * FREEZE_INTERVAL;
+ int i;
+ for (i = 0; i < 2; i++) {
+ c->paths[i] = av_mallocz(max_paths * sizeof(**c->paths));
+ c->node_buf[i] = av_mallocz(2 * frontier * sizeof(**c->node_buf));
+ c->nodep_buf[i] = av_mallocz(2 * frontier * sizeof(**c->nodep_buf));
+ }
+ }
+
+ return 0;
+}
+
+static av_cold int g722_close(AVCodecContext *avctx)
+{
+ G722Context *c = avctx->priv_data;
+ int i;
+ for (i = 0; i < 2; i++) {
+ av_freep(&c->paths[i]);
+ av_freep(&c->node_buf[i]);
+ av_freep(&c->nodep_buf[i]);
+ }
return 0;
}
@@ -351,6 +387,164 @@ static inline int encode_low(const struc
return (diff < 0 ? (i < 2 ? 63 : 33) : 61) - i;
}
+static int g722_encode_trellis(AVCodecContext *avctx,
+ uint8_t *dst, int buf_size, void *data)
+{
+ G722Context *c = avctx->priv_data;
+ const int16_t *samples = data;
+ int i, j, k;
+ int frontier = 1 << avctx->trellis;
+ struct TrellisNode **nodes[2];
+ struct TrellisNode **nodes_next[2];
+ int pathn[2] = {0, 0}, froze = -1;
+ struct TrellisPath *p[2];
+
+ for (i = 0; i < 2; i++) {
+ nodes[i] = c->nodep_buf[i];
+ nodes_next[i] = c->nodep_buf[i] + frontier;
+ memset(c->nodep_buf[i], 0, 2 * frontier * sizeof(*c->nodep_buf));
+ nodes[i][0] = c->node_buf[i] + frontier;
+ nodes[i][0]->ssd = 0;
+ nodes[i][0]->path = 0;
+ nodes[i][0]->state = c->band[i];
+ }
+
+ for (i = 0; i < buf_size >> 1; i++) {
+ int xlow, xhigh;
+ struct TrellisNode *next[2];
+ int heap_pos[2] = {0, 0};
+
+ for (j = 0; j < 2; j++) {
+ next[j] = c->node_buf[j] + frontier*(i & 1);
+ memset(nodes_next[j], 0, frontier * sizeof(**nodes_next));
+ }
+
+ filter_samples(c, &samples[2*i], &xlow, &xhigh);
+
+ for (j = 0; j < frontier && nodes[0][j]; j++) {
+ /* Only k >> 2 affects the future adaptive state, therefore testing
+ * small steps that don't change k >> 2 is useless, the orignal
+ * value from encode_low is better than them. Since we step k
+ * in steps of 4, make sure range is a multiple of 4, so that
+ * we don't miss the original value from encode_low. */
+ int range = j < frontier/2 ? 4 : 0;
+ struct TrellisNode *cur_node = nodes[0][j];
+
+ int ilow = encode_low(&cur_node->state, xlow);
+
+ for (k = ilow - range; k <= ilow + range && k <= 63; k += 4) {
+ int decoded, dec_diff, pos;
+ uint32_t ssd;
+ struct TrellisNode* node;
+
+ if (k < 0)
+ continue;
+
+ decoded = av_clip((cur_node->state.scale_factor *
+ low_inv_quant6[k] >> 10)
+ + cur_node->state.s_predictor, -16384, 16383);
+ dec_diff = xlow - decoded;
+
+#define STORE_NODE(index, UPDATE, VALUE)\
+ ssd = cur_node->ssd + dec_diff*dec_diff;\
+ /* Check for wraparound. Using 64 bit ssd counters would \
+ * be simpler, but is slower on x86 32 bit. */\
+ if (ssd < cur_node->ssd)\
+ continue;\
+ if (heap_pos[index] < frontier) {\
+ pos = heap_pos[index]++;\
+ assert(pathn[index] < FREEZE_INTERVAL * frontier);\
+ node = nodes_next[index][pos] = next[index]++;\
+ node->path = pathn[index]++;\
+ } else {\
+ /* Try to replace one of the leaf nodes with the new \
+ * one, but not always testing the same leaf position */\
+ pos = (frontier>>1) + (heap_pos[index] & ((frontier>>1) - 1));\
+ if (ssd >= nodes_next[index][pos]->ssd)\
+ continue;\
+ heap_pos[index]++;\
+ node = nodes_next[index][pos];\
+ }\
+ node->ssd = ssd;\
+ node->state = cur_node->state;\
+ UPDATE;\
+ c->paths[index][node->path].value = VALUE;\
+ c->paths[index][node->path].prev = cur_node->path;\
+ /* Sift the newly inserted node up in the heap to restore \
+ * the heap property */\
+ while (pos > 0) {\
+ int parent = (pos - 1) >> 1;\
+ if (nodes_next[index][parent]->ssd <= ssd)\
+ break;\
+ FFSWAP(struct TrellisNode*, nodes_next[index][parent],\
+ nodes_next[index][pos]);\
+ pos = parent;\
+ }
+ STORE_NODE(0, update_low_predictor(&node->state, k >> 2), k);
+ }
+ }
+
+ for (j = 0; j < frontier && nodes[1][j]; j++) {
+ int ihigh;
+ struct TrellisNode *cur_node = nodes[1][j];
+
+ /* We don't try to get any initial guess for ihigh via
+ * encode_high - since there's only 4 possible values, test
+ * them all. Testing all of these gives a much, much larger
+ * gain than testing a larger range around ilow. */
+ for (ihigh = 0; ihigh < 4; ihigh++) {
+ int dhigh, decoded, dec_diff, pos;
+ uint32_t ssd;
+ struct TrellisNode* node;
+
+ dhigh = cur_node->state.scale_factor *
+ high_inv_quant[ihigh] >> 10;
+ decoded = av_clip(dhigh + cur_node->state.s_predictor,
+ -16384, 16383);
+ dec_diff = xhigh - decoded;
+
+ STORE_NODE(1, update_high_predictor(&node->state, dhigh, ihigh), ihigh);
+ }
+ }
+
+ for (j = 0; j < 2; j++) {
+ FFSWAP(struct TrellisNode**, nodes[j], nodes_next[j]);
+
+ if (nodes[j][0]->ssd > (1 << 16)) {
+ for (k = 1; k < frontier && nodes[j][k]; k++)
+ nodes[j][k]->ssd -= nodes[j][0]->ssd;
+ nodes[j][0]->ssd = 0;
+ }
+ }
+
+ if (i == froze + FREEZE_INTERVAL) {
+ p[0] = &c->paths[0][nodes[0][0]->path];
+ p[1] = &c->paths[1][nodes[1][0]->path];
+ for (j = i; j > froze; j--) {
+ dst[j] = p[1]->value << 6 | p[0]->value;
+ p[0] = &c->paths[0][p[0]->prev];
+ p[1] = &c->paths[1][p[1]->prev];
+ }
+ froze = i;
+ pathn[0] = pathn[1] = 0;
+ memset(nodes[0] + 1, 0, (frontier - 1)*sizeof(**nodes));
+ memset(nodes[1] + 1, 0, (frontier - 1)*sizeof(**nodes));
+ }
+ }
+
+ p[0] = &c->paths[0][nodes[0][0]->path];
+ p[1] = &c->paths[1][nodes[1][0]->path];
+ for (j = i; j > froze; j--) {
+ dst[j] = p[1]->value << 6 | p[0]->value;
+ p[0] = &c->paths[0][p[0]->prev];
+ p[1] = &c->paths[1][p[1]->prev];
+ }
+ c->band[0] = nodes[0][0]->state;
+ c->band[1] = nodes[1][0]->state;
+
+ return i;
+}
+
static int g722_encode_frame(AVCodecContext *avctx,
uint8_t *dst, int buf_size, void *data)
{
@@ -358,6 +552,9 @@ static int g722_encode_frame(AVCodecCont
const int16_t *samples = data;
int i;
+ if (avctx->trellis)
+ return g722_encode_trellis(avctx, dst, buf_size, data);
+
for (i = 0; i < buf_size >> 1; i++) {
int xlow, xhigh, ihigh, ilow;
filter_samples(c, &samples[2*i], &xlow, &xhigh);
@@ -377,6 +574,7 @@ AVCodec adpcm_g722_encoder = {
.id = CODEC_ID_ADPCM_G722,
.priv_data_size = sizeof(G722Context),
.init = g722_init,
+ .close = g722_close,
.encode = g722_encode_frame,
.long_name = NULL_IF_CONFIG_SMALL("G.722 ADPCM"),
.sample_fmts = (enum AVSampleFormat[]){AV_SAMPLE_FMT_S16,AV_SAMPLE_FMT_NONE},
More information about the ffmpeg-cvslog
mailing list