alac: simplify 1st order prediction and reading of warm-up samples

[ffmpeg] / libavcodec / wmalosslessdec.c

diff --git a/libavcodec/wmalosslessdec.c b/libavcodec/wmalosslessdec.c
index 3ee6285d79d19b5fc76de7e7bca159c3aded9a7b..cb7f66715bcc7abbe7df90fc1d6f89c6c8c17cd4 100644 (file)
--- a/libavcodec/wmalosslessdec.c
+++ b/libavcodec/wmalosslessdec.c
@@ -22,6 +22,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include "libavutil/attributes.h"
 #include "avcodec.h"
 #include "internal.h"
 #include "get_bits.h"
@@ -173,7 +174,7 @@ static av_cold int decode_init(AVCodecContext *avctx)
     WmallDecodeCtx *s  = avctx->priv_data;
     uint8_t *edata_ptr = avctx->extradata;
     unsigned int channel_mask;
-    int i, log2_max_num_subframes, num_possible_block_sizes;
+    int i, log2_max_num_subframes;
 
     s->avctx = avctx;
     init_put_bits(&s->pb, s->frame_data, MAX_FRAMESIZE);
@@ -225,7 +226,6 @@ static av_cold int decode_init(AVCodecContext *avctx)
     s->max_subframe_len_bit = 0;
     s->subframe_len_bits    = av_log2(log2_max_num_subframes) + 1;
 
-    num_possible_block_sizes     = log2_max_num_subframes + 1;
     s->min_samples_per_subframe  = s->samples_per_frame / s->max_num_subframes;
     s->dynamic_range_compression = s->decode_flags & 0x80;
     s->bV3RTM                    = s->decode_flags & 0x100;
@@ -655,9 +655,9 @@ static void mclms_predict(WmallDecodeCtx *s, int icoef, int *pred)
     int num_channels = s->num_channels;
 
     for (ich = 0; ich < num_channels; ich++) {
+        pred[ich] = 0;
         if (!s->is_channel_coded[ich])
             continue;
-        pred[ich] = 0;
         for (i = 0; i < order * num_channels; i++)
             pred[ich] += s->mclms_prevvalues[i + s->mclms_recent] *
                          s->mclms_coeffs[i + order * num_channels * ich];
@@ -790,7 +790,7 @@ static void revert_inter_ch_decorr(WmallDecodeCtx *s, int tile_size)
 {
     if (s->num_channels != 2)
         return;
-    else if (s->is_channel_coded[0] && s->is_channel_coded[1]) {
+    else if (s->is_channel_coded[0] || s->is_channel_coded[1]) {
         int icoef;
         for (icoef = 0; icoef < tile_size; icoef++) {
             s->channel_residues[0][icoef] -= s->channel_residues[1][icoef] >> 1;
@@ -936,6 +936,11 @@ static int decode_subframe(WmallDecodeCtx *s)
 
     if (rawpcm_tile) {
         int bits = s->bits_per_sample - padding_zeroes;
+        if (bits <= 0) {
+            av_log(s->avctx, AV_LOG_ERROR,
+                   "Invalid number of padding bits in raw PCM tile\n");
+            return AVERROR_INVALIDDATA;
+        }
         av_dlog(s->avctx, "RAWPCM %d bits per sample. "
                 "total %d bits, remain=%d\n", bits,
                 bits * s->num_channels * subframe_len, get_bits_count(&s->gb));
@@ -951,6 +956,8 @@ static int decode_subframe(WmallDecodeCtx *s)
                 else
                     use_normal_update_speed(s, i);
                 revert_cdlms(s, i, 0, subframe_len);
+            } else {
+                memset(s->channel_residues[i], 0, sizeof(**s->channel_residues) * subframe_len);
             }
     }
     if (s->do_mclms)
@@ -973,10 +980,10 @@ static int decode_subframe(WmallDecodeCtx *s)
 
         for (j = 0; j < subframe_len; j++) {
             if (s->bits_per_sample == 16) {
-                *s->samples_16[c] = (int16_t) s->channel_residues[c][j];
+                *s->samples_16[c] = (int16_t) s->channel_residues[c][j] << padding_zeroes;
                 s->samples_16[c] += s->num_channels;
             } else {
-                *s->samples_32[c] = s->channel_residues[c][j];
+                *s->samples_32[c] = s->channel_residues[c][j] << padding_zeroes;
                 s->samples_32[c] += s->num_channels;
             }
         }
@@ -1035,7 +1042,7 @@ static int decode_frame(WmallDecodeCtx *s)
     /* no idea what these are for, might be the number of samples
        that need to be skipped at the beginning or end of a stream */
     if (get_bits1(gb)) {
-        int skip;
+        int av_unused skip;
 
         /* usually true for the first frame */
         if (get_bits1(gb)) {
@@ -1153,14 +1160,6 @@ static void save_bits(WmallDecodeCtx *s, GetBitContext* gb, int len,
     skip_bits(&s->gb, s->frame_offset);
 }
 
-/**
- * @brief Decode a single WMA packet.
- * @param avctx     codec context
- * @param data      the output buffer
- * @param data_size number of bytes that were written to the output buffer
- * @param avpkt     input packet
- * @return number of bytes that were read from the input buffer
- */
 static int decode_packet(AVCodecContext *avctx, void *data, int *got_frame_ptr,
                          AVPacket* avpkt)
 {
@@ -1168,8 +1167,9 @@ static int decode_packet(AVCodecContext *avctx, void *data, int *got_frame_ptr,
     GetBitContext* gb  = &s->pgb;
     const uint8_t* buf = avpkt->data;
     int buf_size       = avpkt->size;
-    int num_bits_prev_frame, packet_sequence_number,
-        seekable_frame_in_packet, spliced_packet;
+    int num_bits_prev_frame, packet_sequence_number, spliced_packet;
+
+    s->frame.nb_samples = 0;
 
     if (s->packet_done || s->packet_loss) {
         s->packet_done = 0;
@@ -1184,9 +1184,11 @@ static int decode_packet(AVCodecContext *avctx, void *data, int *got_frame_ptr,
 
         /* parse packet header */
         init_get_bits(gb, buf, s->buf_bit_size);
-        packet_sequence_number   = get_bits(gb, 4);
-        seekable_frame_in_packet = get_bits1(gb);
-        spliced_packet           = get_bits1(gb);
+        packet_sequence_number = get_bits(gb, 4);
+        skip_bits(gb, 1);   // Skip seekable_frame_in_packet, currently ununused
+        spliced_packet = get_bits1(gb);
+        if (spliced_packet)
+            av_log_missing_feature(avctx, "Bitstream splicing", 1);
 
         /* get number of bits that need to be added to the previous frame */
         num_bits_prev_frame = get_bits(gb, s->log2_frame_size);
@@ -1212,7 +1214,7 @@ static int decode_packet(AVCodecContext *avctx, void *data, int *got_frame_ptr,
             save_bits(s, gb, num_bits_prev_frame, 1);
 
             /* decode the cross packet frame if it is valid */
-            if (!s->packet_loss)
+            if (num_bits_prev_frame < remaining_packet_bits && !s->packet_loss)
                 decode_frame(s);
         } else if (s->num_saved_bits - s->frame_offset) {
             av_dlog(avctx, "ignoring %x previously saved bits\n",