avcodec: add Ulead DV audio decoder

Fixes #1564.

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

1 files changed, 144 insertions, 0 deletions

diff --git a/libavcodec/dvaudiodec.c b/libavcodec/dvaudiodec.c
new file mode 100644
index 0000000..84db509
--- /dev/null
+++ b/libavcodec/dvaudiodec.c
@@ -0,0 +1,144 @@
+/*
+ * Copyright (c) 2012 Laurent Aimar
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libavutil/intreadwrite.h"
+#include "avcodec.h"
+#include "internal.h"
+
+typedef struct DVAudioContext {
+    int block_size;
+    int is_12bit;
+    int is_pal;
+    int16_t shuffle[2000];
+} DVAudioContext;
+
+static av_cold int decode_init(AVCodecContext *avctx)
+{
+    DVAudioContext *s = avctx->priv_data;
+    int i;
+
+    if (avctx->channels > 2) {
+        av_log(avctx, AV_LOG_ERROR, "invalid number of channels\n");
+        return AVERROR(EINVAL);
+    }
+
+    if (avctx->codec_tag == 0x0215) {
+        s->block_size = 7200;
+        s->is_pal = 0;
+    } else if (avctx->codec_tag == 0x0216) {
+        s->block_size = 8640;
+        s->is_pal = 1;
+    } else {
+        return AVERROR(EINVAL);
+    }
+
+    s->is_12bit = avctx->bits_per_raw_sample == 12;
+    avctx->sample_fmt = AV_SAMPLE_FMT_S16;
+
+    for (i = 0; i < FF_ARRAY_ELEMS(s->shuffle); i++) {
+        const unsigned a = s->is_pal ? 18 : 15;
+        const unsigned b = 3 * a;
+
+        s->shuffle[i] = 80 * ((21 * (i % 3) + 9 * (i / 3) + ((i / a) % 3)) % b) +
+                         (2 + s->is_12bit) * (i / b) + 8;
+    }
+
+    return 0;
+}
+
+static inline int dv_get_audio_sample_count(const uint8_t *buffer, int dsf)
+{
+    int samples = buffer[0] & 0x3f; /* samples in this frame - min samples */
+
+    switch ((buffer[3] >> 3) & 0x07) {
+    case 0:
+        return samples + (dsf ? 1896 : 1580);
+    case 1:
+        return samples + (dsf ? 1742 : 1452);
+    case 2:
+    default:
+        return samples + (dsf ? 1264 : 1053);
+    }
+}
+
+static inline uint16_t dv_audio_12to16(uint16_t sample)
+{
+    uint16_t shift, result;
+
+    sample = (sample < 0x800) ? sample : sample | 0xf000;
+    shift  = (sample & 0xf00) >> 8;
+
+    if (shift < 0x2 || shift > 0xd) {
+        result = sample;
+    } else if (shift < 0x8) {
+        shift--;
+        result = (sample - (256 * shift)) << shift;
+    } else {
+        shift  = 0xe - shift;
+        result = ((sample + ((256 * shift) + 1)) << shift) - 1;
+    }
+
+    return result;
+}
+
+static int decode_frame(AVCodecContext *avctx, void *data,
+                        int *got_frame_ptr, AVPacket *pkt)
+{
+    DVAudioContext *s = avctx->priv_data;
+    AVFrame *frame = data;
+    const uint8_t *src = pkt->data;
+    int16_t *dst;
+    int ret, i;
+
+    if (pkt->size != s->block_size)
+        return AVERROR_INVALIDDATA;
+
+    frame->nb_samples = dv_get_audio_sample_count(pkt->data + 244, s->is_pal);
+    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
+        return ret;
+    dst = (int16_t *)frame->data[0];
+
+    for (i = 0; i < frame->nb_samples; i++) {
+       const uint8_t *v = &src[s->shuffle[i]];
+
+       if (s->is_12bit) {
+           *dst++ = dv_audio_12to16((v[0] << 4) | ((v[2] >> 4) & 0x0f));
+           *dst++ = dv_audio_12to16((v[1] << 4) | ((v[2] >> 0) & 0x0f));
+       } else {
+           *dst++ = AV_RB16(&v[0]);
+           *dst++ = AV_RB16(&v[s->is_pal ? 4320 : 3600]);
+       }
+    }
+
+    *got_frame_ptr = 1;
+
+    return pkt->size;
+}
+
+AVCodec ff_dvaudio_decoder = {
+    .name           = "dvaudio",
+    .long_name      = NULL_IF_CONFIG_SMALL("Ulead DV Audio"),
+    .type           = AVMEDIA_TYPE_AUDIO,
+    .id             = AV_CODEC_ID_DVAUDIO,
+    .init           = decode_init,
+    .decode         = decode_frame,
+    .capabilities   = AV_CODEC_CAP_DR1,
+    .priv_data_size = sizeof(DVAudioContext),
+};