]> git.sesse.net Git - ffmpeg/blobdiff - libavcodec/dpcm.c
dpcm: use AVCodecContext.channels instead of keeping a private copy
[ffmpeg] / libavcodec / dpcm.c
index bd3ad7fd0f2943164a7639d710a26a65d6214053..fb1c7ce6f20fef43ef807175831b75859b9ecb3d 100644 (file)
@@ -1,48 +1,55 @@
 /*
  * Assorted DPCM codecs
- * Copyright (c) 2003 The ffmpeg Project.
+ * Copyright (c) 2003 The ffmpeg Project
  *
- * This library is free software; you can redistribute it and/or
+ * This file is part of Libav.
+ *
+ * Libav 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 of the License, or (at your option) any later version.
+ * version 2.1 of the License, or (at your option) any later version.
  *
- * This library is distributed in the hope that it will be useful,
+ * Libav 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 this library; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ * License along with Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 /**
- * @file: dpcm.c
+ * @file
  * Assorted DPCM (differential pulse code modulation) audio codecs
  * by Mike Melanson (melanson@pcisys.net)
+ * Xan DPCM decoder by Mario Brito (mbrito@student.dei.uc.pt)
  * for more information on the specific data formats, visit:
  *   http://www.pcisys.net/~melanson/codecs/simpleaudio.html
+ * SOL DPCMs implemented by Konstantin Shishkov
+ *
+ * Note about using the Xan DPCM decoder: Xan DPCM is used in AVI files
+ * found in the Wing Commander IV computer game. These AVI files contain
+ * WAVEFORMAT headers which report the audio format as 0x01: raw PCM.
+ * Clearly incorrect. To detect Xan DPCM, you will probably have to
+ * special-case your AVI demuxer to use Xan DPCM if the file uses 'Xxan'
+ * (Xan video) for its video codec. Alternately, such AVI files also contain
+ * the fourcc 'Axan' in the 'auds' chunk of the AVI header.
  */
 
+#include "libavutil/intreadwrite.h"
 #include "avcodec.h"
+#include "bytestream.h"
+#include "mathops.h"
 
 typedef struct DPCMContext {
-    int channels;
-    short roq_square_array[256];
-    int last_delta[2];
+    AVFrame frame;
+    int16_t roq_square_array[256];
+    int sample[2];                  ///< previous sample (for SOL_DPCM)
+    const int8_t *sol_table;        ///< delta table for SOL_DPCM
 } DPCMContext;
 
-#define SATURATE_S16(x)  if (x < -32768) x = -32768; \
-  else if (x > 32767) x = 32767;
-#define SE_16BIT(x)  if (x & 0x8000) x -= 0x10000;
-#define LE_16(x)  ((((uint8_t*)(x))[1] << 8) | ((uint8_t*)(x))[0])
-#define LE_32(x)  ((((uint8_t*)(x))[3] << 24) | \
-                   (((uint8_t*)(x))[2] << 16) | \
-                   (((uint8_t*)(x))[1] << 8) | \
-                    ((uint8_t*)(x))[0])
-
-static int interplay_delta_table[] = {
+static const int16_t interplay_delta_table[] = {
          0,      1,      2,      3,      4,      5,      6,      7,
          8,      9,     10,     11,     12,     13,     14,     15,
         16,     17,     18,     19,     20,     21,     22,     23,
@@ -78,123 +85,261 @@ static int interplay_delta_table[] = {
 
 };
 
-static int dpcm_decode_init(AVCodecContext *avctx)
+static const int8_t sol_table_old[16] = {
+      0x0,  0x1,  0x2,  0x3,  0x6,  0xA,  0xF, 0x15,
+    -0x15, -0xF, -0xA, -0x6, -0x3, -0x2, -0x1,  0x0
+};
+
+static const int8_t sol_table_new[16] = {
+    0x0,  0x1,  0x2,  0x3,  0x6,  0xA,  0xF,  0x15,
+    0x0, -0x1, -0x2, -0x3, -0x6, -0xA, -0xF, -0x15
+};
+
+static const int16_t sol_table_16[128] = {
+    0x000, 0x008, 0x010, 0x020, 0x030, 0x040, 0x050, 0x060, 0x070, 0x080,
+    0x090, 0x0A0, 0x0B0, 0x0C0, 0x0D0, 0x0E0, 0x0F0, 0x100, 0x110, 0x120,
+    0x130, 0x140, 0x150, 0x160, 0x170, 0x180, 0x190, 0x1A0, 0x1B0, 0x1C0,
+    0x1D0, 0x1E0, 0x1F0, 0x200, 0x208, 0x210, 0x218, 0x220, 0x228, 0x230,
+    0x238, 0x240, 0x248, 0x250, 0x258, 0x260, 0x268, 0x270, 0x278, 0x280,
+    0x288, 0x290, 0x298, 0x2A0, 0x2A8, 0x2B0, 0x2B8, 0x2C0, 0x2C8, 0x2D0,
+    0x2D8, 0x2E0, 0x2E8, 0x2F0, 0x2F8, 0x300, 0x308, 0x310, 0x318, 0x320,
+    0x328, 0x330, 0x338, 0x340, 0x348, 0x350, 0x358, 0x360, 0x368, 0x370,
+    0x378, 0x380, 0x388, 0x390, 0x398, 0x3A0, 0x3A8, 0x3B0, 0x3B8, 0x3C0,
+    0x3C8, 0x3D0, 0x3D8, 0x3E0, 0x3E8, 0x3F0, 0x3F8, 0x400, 0x440, 0x480,
+    0x4C0, 0x500, 0x540, 0x580, 0x5C0, 0x600, 0x640, 0x680, 0x6C0, 0x700,
+    0x740, 0x780, 0x7C0, 0x800, 0x900, 0xA00, 0xB00, 0xC00, 0xD00, 0xE00,
+    0xF00, 0x1000, 0x1400, 0x1800, 0x1C00, 0x2000, 0x3000, 0x4000
+};
+
+
+static av_cold int dpcm_decode_init(AVCodecContext *avctx)
 {
     DPCMContext *s = avctx->priv_data;
     int i;
-    short square;
 
-    s->channels = avctx->channels;
+    if (avctx->channels < 1 || avctx->channels > 2) {
+        av_log(avctx, AV_LOG_INFO, "invalid number of channels\n");
+        return AVERROR(EINVAL);
+    }
+
+    s->sample[0] = s->sample[1] = 0;
 
     switch(avctx->codec->id) {
 
-    case CODEC_ID_ROQ_DPCM:
+    case AV_CODEC_ID_ROQ_DPCM:
         /* initialize square table */
         for (i = 0; i < 128; i++) {
-            square = i * i;
-            s->roq_square_array[i] = square;
+            int16_t square = i * i;
+            s->roq_square_array[i      ] =  square;
             s->roq_square_array[i + 128] = -square;
         }
         break;
 
+    case AV_CODEC_ID_SOL_DPCM:
+        switch(avctx->codec_tag){
+        case 1:
+            s->sol_table = sol_table_old;
+            s->sample[0] = s->sample[1] = 0x80;
+            break;
+        case 2:
+            s->sol_table = sol_table_new;
+            s->sample[0] = s->sample[1] = 0x80;
+            break;
+        case 3:
+            break;
+        default:
+            av_log(avctx, AV_LOG_ERROR, "Unknown SOL subcodec\n");
+            return -1;
+        }
+        break;
+
     default:
         break;
     }
 
+    if (avctx->codec->id == AV_CODEC_ID_SOL_DPCM && avctx->codec_tag != 3)
+        avctx->sample_fmt = AV_SAMPLE_FMT_U8;
+    else
+        avctx->sample_fmt = AV_SAMPLE_FMT_S16;
+
+    avcodec_get_frame_defaults(&s->frame);
+    avctx->coded_frame = &s->frame;
+
     return 0;
 }
 
-static int dpcm_decode_frame(AVCodecContext *avctx,
-                             void *data, int *data_size,
-                             uint8_t *buf, int buf_size)
+
+static int dpcm_decode_frame(AVCodecContext *avctx, void *data,
+                             int *got_frame_ptr, AVPacket *avpkt)
 {
+    int buf_size = avpkt->size;
     DPCMContext *s = avctx->priv_data;
-    int in, out = 0;
-    int i;
+    int out = 0, ret;
     int predictor[2];
-    int channel_number = 0;
-    short *output_samples = data;
-    int sequence_number;
+    int ch = 0;
+    int stereo = avctx->channels - 1;
+    int16_t *output_samples, *samples_end;
+    GetByteContext gb;
+
+    if (stereo && (buf_size & 1))
+        buf_size--;
+    bytestream2_init(&gb, avpkt->data, buf_size);
+
+    /* calculate output size */
+    switch(avctx->codec->id) {
+    case AV_CODEC_ID_ROQ_DPCM:
+        out = buf_size - 8;
+        break;
+    case AV_CODEC_ID_INTERPLAY_DPCM:
+        out = buf_size - 6 - avctx->channels;
+        break;
+    case AV_CODEC_ID_XAN_DPCM:
+        out = buf_size - 2 * avctx->channels;
+        break;
+    case AV_CODEC_ID_SOL_DPCM:
+        if (avctx->codec_tag != 3)
+            out = buf_size * 2;
+        else
+            out = buf_size;
+        break;
+    }
+    if (out <= 0) {
+        av_log(avctx, AV_LOG_ERROR, "packet is too small\n");
+        return AVERROR(EINVAL);
+    }
+
+    /* get output buffer */
+    s->frame.nb_samples = out / avctx->channels;
+    if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
+        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
+        return ret;
+    }
+    output_samples = (int16_t *)s->frame.data[0];
+    samples_end = output_samples + out;
 
     switch(avctx->codec->id) {
 
-    case CODEC_ID_ROQ_DPCM:
-        if (s->channels == 1)
-            predictor[0] = LE_16(&buf[6]);
-        else {
-            predictor[0] = buf[7] << 8;
-            predictor[1] = buf[6] << 8;
+    case AV_CODEC_ID_ROQ_DPCM:
+        bytestream2_skipu(&gb, 6);
+
+        if (stereo) {
+            predictor[1] = sign_extend(bytestream2_get_byteu(&gb) << 8, 16);
+            predictor[0] = sign_extend(bytestream2_get_byteu(&gb) << 8, 16);
+        } else {
+            predictor[0] = sign_extend(bytestream2_get_le16u(&gb), 16);
         }
-        SE_16BIT(predictor[0]);
-        SE_16BIT(predictor[1]);
 
         /* decode the samples */
-        for (in = 8, out = 0; in < buf_size; in++, out++) {
-            predictor[channel_number] += s->roq_square_array[buf[in]];
-            SATURATE_S16(predictor[channel_number]);
-            output_samples[out] = predictor[channel_number];
+        while (output_samples < samples_end) {
+            predictor[ch] += s->roq_square_array[bytestream2_get_byteu(&gb)];
+            predictor[ch]  = av_clip_int16(predictor[ch]);
+            *output_samples++ = predictor[ch];
 
             /* toggle channel */
-            channel_number ^= s->channels - 1;
+            ch ^= stereo;
         }
         break;
 
-    case CODEC_ID_INTERPLAY_DPCM:
-        in = 0;
-        sequence_number = LE_16(&buf[in]);
-        in += 6;  /* skip over the stream mask and stream length */
-        if (sequence_number == 1) {
-            predictor[0] = LE_16(&buf[in]);
-            in += 2;
-            SE_16BIT(predictor[0])
-            if (s->channels == 2) {
-                predictor[1] = LE_16(&buf[in]);
-                SE_16BIT(predictor[1])
-                in += 2;
-            }
-        } else {
-            for (i = 0; i < s->channels; i++)
-                predictor[i] = s->last_delta[i];
+    case AV_CODEC_ID_INTERPLAY_DPCM:
+        bytestream2_skipu(&gb, 6);  /* skip over the stream mask and stream length */
+
+        for (ch = 0; ch < avctx->channels; ch++) {
+            predictor[ch] = sign_extend(bytestream2_get_le16u(&gb), 16);
+            *output_samples++ = predictor[ch];
         }
 
-        while (in < buf_size) {
-            predictor[channel_number] += interplay_delta_table[buf[in++]];
-            SATURATE_S16(predictor[channel_number]);
-            output_samples[out++] = predictor[channel_number];
+        ch = 0;
+        while (output_samples < samples_end) {
+            predictor[ch] += interplay_delta_table[bytestream2_get_byteu(&gb)];
+            predictor[ch]  = av_clip_int16(predictor[ch]);
+            *output_samples++ = predictor[ch];
+
+            /* toggle channel */
+            ch ^= stereo;
+        }
+        break;
+
+    case AV_CODEC_ID_XAN_DPCM:
+    {
+        int shift[2] = { 4, 4 };
+
+        for (ch = 0; ch < avctx->channels; ch++)
+            predictor[ch] = sign_extend(bytestream2_get_le16u(&gb), 16);
+
+        ch = 0;
+        while (output_samples < samples_end) {
+            int diff = bytestream2_get_byteu(&gb);
+            int n    = diff & 3;
+
+            if (n == 3)
+                shift[ch]++;
+            else
+                shift[ch] -= (2 * n);
+            diff = sign_extend((diff &~ 3) << 8, 16);
+
+            /* saturate the shifter to a lower limit of 0 */
+            if (shift[ch] < 0)
+                shift[ch] = 0;
+
+            diff >>= shift[ch];
+            predictor[ch] += diff;
+
+            predictor[ch] = av_clip_int16(predictor[ch]);
+            *output_samples++ = predictor[ch];
 
             /* toggle channel */
-            channel_number ^= s->channels - 1;
+            ch ^= stereo;
         }
+        break;
+    }
+    case AV_CODEC_ID_SOL_DPCM:
+        if (avctx->codec_tag != 3) {
+            uint8_t *output_samples_u8 = s->frame.data[0],
+                    *samples_end_u8 = output_samples_u8 + out;
+            while (output_samples_u8 < samples_end_u8) {
+                int n = bytestream2_get_byteu(&gb);
 
-        /* save predictors for next round */
-        for (i = 0; i < s->channels; i++)
-            s->last_delta[i] = predictor[i];
+                s->sample[0] += s->sol_table[n >> 4];
+                s->sample[0]  = av_clip_uint8(s->sample[0]);
+                *output_samples_u8++ = s->sample[0];
 
+                s->sample[stereo] += s->sol_table[n & 0x0F];
+                s->sample[stereo]  = av_clip_uint8(s->sample[stereo]);
+                *output_samples_u8++ = s->sample[stereo];
+            }
+        } else {
+            while (output_samples < samples_end) {
+                int n = bytestream2_get_byteu(&gb);
+                if (n & 0x80) s->sample[ch] -= sol_table_16[n & 0x7F];
+                else          s->sample[ch] += sol_table_16[n & 0x7F];
+                s->sample[ch] = av_clip_int16(s->sample[ch]);
+                *output_samples++ = s->sample[ch];
+                /* toggle channel */
+                ch ^= stereo;
+            }
+        }
         break;
     }
 
-    *data_size = out * sizeof(short);
-    return buf_size;
+    *got_frame_ptr   = 1;
+    *(AVFrame *)data = s->frame;
+
+    return avpkt->size;
 }
 
-AVCodec roq_dpcm_decoder = {
-    "roq_dpcm",
-    CODEC_TYPE_AUDIO,
-    CODEC_ID_ROQ_DPCM,
-    sizeof(DPCMContext),
-    dpcm_decode_init,
-    NULL,
-    NULL,
-    dpcm_decode_frame,
-};
+#define DPCM_DECODER(id_, name_, long_name_)                \
+AVCodec ff_ ## name_ ## _decoder = {                        \
+    .name           = #name_,                               \
+    .type           = AVMEDIA_TYPE_AUDIO,                   \
+    .id             = id_,                                  \
+    .priv_data_size = sizeof(DPCMContext),                  \
+    .init           = dpcm_decode_init,                     \
+    .decode         = dpcm_decode_frame,                    \
+    .capabilities   = CODEC_CAP_DR1,                        \
+    .long_name      = NULL_IF_CONFIG_SMALL(long_name_),     \
+}
 
-AVCodec interplay_dpcm_decoder = {
-    "interplay_dpcm",
-    CODEC_TYPE_AUDIO,
-    CODEC_ID_INTERPLAY_DPCM,
-    sizeof(DPCMContext),
-    dpcm_decode_init,
-    NULL,
-    NULL,
-    dpcm_decode_frame,
-};
+DPCM_DECODER(AV_CODEC_ID_INTERPLAY_DPCM, interplay_dpcm, "DPCM Interplay");
+DPCM_DECODER(AV_CODEC_ID_ROQ_DPCM,       roq_dpcm,       "DPCM id RoQ");
+DPCM_DECODER(AV_CODEC_ID_SOL_DPCM,       sol_dpcm,       "DPCM Sol");
+DPCM_DECODER(AV_CODEC_ID_XAN_DPCM,       xan_dpcm,       "DPCM Xan");