[FFmpeg-devel] [PATCH] ADPCM IMA WAV 2, 3 and 5 bits decoder

Paul B Mahol onemda at gmail.com
Tue Jul 2 23:30:44 CEST 2013


Signed-off-by: Paul B Mahol <onemda at gmail.com>
---

Fixes #625.

Stereo files on that ticket do not match specification and lacks sanity,
as samples are most likely incorrectly interleaved.

---
 libavcodec/Makefile     |  2 +-
 libavcodec/adpcm.c      | 31 ++++++++++++++++++++++++++-----
 libavcodec/adpcm_data.c | 23 ++++++++++++++++++++++-
 libavcodec/adpcm_data.h |  4 ++++
 libavcodec/adpcm_ima.c  | 26 ++++++++++++++++++++++++++
 libavcodec/adpcm_ima.h  |  4 ++++
 libavcodec/utils.c      |  5 +++--
 7 files changed, 86 insertions(+), 9 deletions(-)
 create mode 100644 libavcodec/adpcm_ima.c
 create mode 100644 libavcodec/adpcm_ima.h

diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index c6cd41b..99a9563 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -597,7 +597,7 @@ OBJS-$(CONFIG_ADPCM_IMA_QT_DECODER)       += adpcm.o adpcm_data.o
 OBJS-$(CONFIG_ADPCM_IMA_QT_ENCODER)       += adpcmenc.o adpcm_data.o
 OBJS-$(CONFIG_ADPCM_IMA_RAD_DECODER)      += adpcm.o adpcm_data.o
 OBJS-$(CONFIG_ADPCM_IMA_SMJPEG_DECODER)   += adpcm.o adpcm_data.o
-OBJS-$(CONFIG_ADPCM_IMA_WAV_DECODER)      += adpcm.o adpcm_data.o
+OBJS-$(CONFIG_ADPCM_IMA_WAV_DECODER)      += adpcm.o adpcm_data.o adpcm_ima.o
 OBJS-$(CONFIG_ADPCM_IMA_WAV_ENCODER)      += adpcmenc.o adpcm_data.o
 OBJS-$(CONFIG_ADPCM_IMA_WS_DECODER)       += adpcm.o adpcm_data.o
 OBJS-$(CONFIG_ADPCM_MS_DECODER)           += adpcm.o adpcm_data.o
diff --git a/libavcodec/adpcm.c b/libavcodec/adpcm.c
index 1259bd4..d51a1f4 100644
--- a/libavcodec/adpcm.c
+++ b/libavcodec/adpcm.c
@@ -35,6 +35,7 @@
 #include "adpcm.h"
 #include "adpcm_data.h"
 #include "internal.h"
+#include "adpcm_ima.h"
 
 /**
  * @file
@@ -118,10 +119,8 @@ static av_cold int adpcm_decode_init(AVCodecContext * avctx)
         c->status[0].step = c->status[1].step = 511;
         break;
     case AV_CODEC_ID_ADPCM_IMA_WAV:
-        if (avctx->bits_per_coded_sample != 4) {
-            av_log(avctx, AV_LOG_ERROR, "Only 4-bit ADPCM IMA WAV files are supported\n");
-            return -1;
-        }
+        if (avctx->bits_per_coded_sample < 2 || avctx->bits_per_coded_sample > 5)
+            return AVERROR_INVALIDDATA;
         break;
     case AV_CODEC_ID_ADPCM_IMA_APC:
         if (avctx->extradata && avctx->extradata_size >= 8) {
@@ -557,10 +556,14 @@ static int get_nb_samples(AVCodecContext *avctx, GetByteContext *gb,
         nb_samples = (buf_size - 4 * ch) * 2 / ch;
         break;
     case AV_CODEC_ID_ADPCM_IMA_WAV:
+    {
+        int bsize = ff_adpcm_ima_block_sizes[avctx->bits_per_coded_sample - 2];
+        int bsamples = ff_adpcm_ima_block_samples[avctx->bits_per_coded_sample - 2];
         if (avctx->block_align > 0)
             buf_size = FFMIN(buf_size, avctx->block_align);
-        nb_samples = 1 + (buf_size - 4 * ch) / (4 * ch) * 8;
+        nb_samples = 1 + (buf_size - 4 * ch) / (bsize * ch) * bsamples;
         break;
+    }
     case AV_CODEC_ID_ADPCM_MS:
         if (avctx->block_align > 0)
             buf_size = FFMIN(buf_size, avctx->block_align);
@@ -720,6 +723,23 @@ static int adpcm_decode_frame(AVCodecContext *avctx, void *data,
             }
         }
 
+        if (avctx->bits_per_coded_sample != 4) {
+            int samples_per_block = ff_adpcm_ima_block_samples[avctx->bits_per_coded_sample - 2];
+            GetBitContext g;
+
+            init_get_bits8(&g, gb.buffer, bytestream2_get_bytes_left(&gb));
+            for (n = 0; n < (nb_samples - 1) / samples_per_block; n++) {
+                for (i = 0; i < avctx->channels; i++) {
+                    cs = &c->status[i];
+                    samples = &samples_p[i][1 + n * samples_per_block];
+                    for (m = 0; m < samples_per_block; m++) {
+                        samples[m] = ff_adpcm_ima_expand_nibble(cs, &g,
+                                        avctx->bits_per_coded_sample - 1);
+                    }
+                }
+            }
+            bytestream2_skip(&gb, avctx->block_align - avctx->channels * 4);
+        } else {
         for (n = 0; n < (nb_samples - 1) / 8; n++) {
             for (i = 0; i < avctx->channels; i++) {
                 cs = &c->status[i];
@@ -731,6 +751,7 @@ static int adpcm_decode_frame(AVCodecContext *avctx, void *data,
                 }
             }
         }
+        }
         break;
     case AV_CODEC_ID_ADPCM_4XM:
         for (i = 0; i < avctx->channels; i++)
diff --git a/libavcodec/adpcm_data.c b/libavcodec/adpcm_data.c
index 0625fc9..1d3e579 100644
--- a/libavcodec/adpcm_data.c
+++ b/libavcodec/adpcm_data.c
@@ -27,12 +27,33 @@
 
 /* ff_adpcm_step_table[] and ff_adpcm_index_table[] are from the ADPCM
    reference source */
-/* This is the index table: */
+static const int8_t adpcm_index_table2[4] = {
+    -1,  2,
+    -1,  2,
+};
+
+static const int8_t adpcm_index_table3[8] = {
+    -1, -1,  1,  2,
+    -1, -1,  1,  2,
+};
+
 const int8_t ff_adpcm_index_table[16] = {
     -1, -1, -1, -1, 2, 4, 6, 8,
     -1, -1, -1, -1, 2, 4, 6, 8,
 };
 
+static const int8_t adpcm_index_table5[32] = {
+    -1, -1, -1, -1, -1, -1, -1, -1, 1, 2, 4, 6, 8, 10, 13, 16,
+    -1, -1, -1, -1, -1, -1, -1, -1, 1, 2, 4, 6, 8, 10, 13, 16,
+};
+
+const int8_t const *ff_adpcm_index_tables[4] = {
+    &adpcm_index_table2[0],
+    &adpcm_index_table3[0],
+    &ff_adpcm_index_table[0],
+    &adpcm_index_table5[0],
+};
+
 /**
  * This is the step table. Note that many programs use slight deviations from
  * this table, but such deviations are negligible:
diff --git a/libavcodec/adpcm_data.h b/libavcodec/adpcm_data.h
index 0ebb7c3..2f62c28 100644
--- a/libavcodec/adpcm_data.h
+++ b/libavcodec/adpcm_data.h
@@ -28,6 +28,10 @@
 
 #include <stdint.h>
 
+static const uint8_t ff_adpcm_ima_block_sizes[4]   = {  8, 12, 4, 20 };
+static const uint8_t ff_adpcm_ima_block_samples[4] = { 32, 32, 8, 32 };
+
+extern const int8_t const *ff_adpcm_index_tables[4];
 extern const int8_t  ff_adpcm_index_table[16];
 extern const int16_t ff_adpcm_step_table[89];
 extern const int16_t ff_adpcm_oki_step_table[49];
diff --git a/libavcodec/adpcm_ima.c b/libavcodec/adpcm_ima.c
new file mode 100644
index 0000000..4a74d64
--- /dev/null
+++ b/libavcodec/adpcm_ima.c
@@ -0,0 +1,26 @@
+#define BITSTREAM_READER_LE
+#include "adpcm_data.h"
+#include "adpcm_ima.h"
+#include "get_bits.h"
+
+inline int16_t ff_adpcm_ima_expand_nibble(ADPCMChannelStatus *c, GetBitContext *gb, int shift)
+{
+    int nibble, step_index, predictor, sign, delta, diff, step;
+
+    nibble = get_bits(gb, shift + 1),
+    step = ff_adpcm_step_table[c->step_index];
+    step_index = c->step_index + ff_adpcm_index_tables[shift - 1][nibble];
+    step_index = av_clip(step_index, 0, 88);
+
+    sign = nibble & (1 << shift);
+    delta = nibble & ((1 << shift) - 1);
+    diff = ((2 * delta + 1) * step) >> shift;
+    predictor = c->predictor;
+    if (sign) predictor -= diff;
+    else predictor += diff;
+
+    c->predictor = av_clip_int16(predictor);
+    c->step_index = step_index;
+
+    return (int16_t)c->predictor;
+}
diff --git a/libavcodec/adpcm_ima.h b/libavcodec/adpcm_ima.h
new file mode 100644
index 0000000..b12fbe1
--- /dev/null
+++ b/libavcodec/adpcm_ima.h
@@ -0,0 +1,4 @@
+#include "adpcm.h"
+#include "get_bits.h"
+
+int16_t ff_adpcm_ima_expand_nibble(ADPCMChannelStatus *c, GetBitContext *gb, int shift);
diff --git a/libavcodec/utils.c b/libavcodec/utils.c
index f26e260..c5dcd8b 100644
--- a/libavcodec/utils.c
+++ b/libavcodec/utils.c
@@ -2759,7 +2759,6 @@ int av_get_bits_per_sample(enum AVCodecID codec_id)
     case AV_CODEC_ID_ADPCM_SBPRO_3:
         return 3;
     case AV_CODEC_ID_ADPCM_SBPRO_4:
-    case AV_CODEC_ID_ADPCM_IMA_WAV:
     case AV_CODEC_ID_ADPCM_IMA_QT:
     case AV_CODEC_ID_ADPCM_SWF:
     case AV_CODEC_ID_ADPCM_MS:
@@ -2899,7 +2898,9 @@ int av_get_audio_frame_duration(AVCodecContext *avctx, int frame_bytes)
                 int blocks = frame_bytes / ba;
                 switch (avctx->codec_id) {
                 case AV_CODEC_ID_ADPCM_IMA_WAV:
-                    return blocks * (1 + (ba - 4 * ch) / (4 * ch) * 8);
+                    if (bps < 2 || bps > 5)
+                        return 0;
+                    return blocks * (1 + (ba - 4 * ch) / (bps * ch) * 8);
                 case AV_CODEC_ID_ADPCM_IMA_DK3:
                     return blocks * (((ba - 16) * 2 / 3 * 4) / ch);
                 case AV_CODEC_ID_ADPCM_IMA_DK4:
-- 
1.7.11.2



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