RealAudio Lossless decoder

Changelog

@@ -13,6 +13,7 @@ version <next>:
 - ID3v2 attached pictures reading and writing
 - WMA Lossless decoder
 - XBM encoder
+- RealAudio Lossless decoder
 
 
 version 0.8:

doc/general.texi

@@ -752,6 +752,7 @@ following image formats are supported:
     @tab Real 28800 bit/s codec
 @item RealAudio 3.0 (dnet)   @tab IX  @tab  X
     @tab Real low bitrate AC-3 codec
+@item RealAudio Lossless     @tab     @tab  X
 @item RealAudio SIPR / ACELP.NET @tab     @tab  X
 @item Shorten                @tab     @tab  X
 @item Sierra VMD audio       @tab     @tab  X

libavcodec/Makefile

@@ -322,6 +322,7 @@ OBJS-$(CONFIG_R210_DECODER)            += r210dec.o
 OBJS-$(CONFIG_RA_144_DECODER)          += ra144dec.o ra144.o celp_filters.o
 OBJS-$(CONFIG_RA_144_ENCODER)          += ra144enc.o ra144.o celp_filters.o
 OBJS-$(CONFIG_RA_288_DECODER)          += ra288.o celp_math.o celp_filters.o
+OBJS-$(CONFIG_RALF_DECODER)            += ralf.o
 OBJS-$(CONFIG_RAWVIDEO_DECODER)        += rawdec.o
 OBJS-$(CONFIG_RAWVIDEO_ENCODER)        += rawenc.o
 OBJS-$(CONFIG_RL2_DECODER)             += rl2.o

libavcodec/allcodecs.c

@@ -280,6 +280,7 @@ void avcodec_register_all(void)
     REGISTER_DECODER (QDM2, qdm2);
     REGISTER_ENCDEC  (RA_144, ra_144);
     REGISTER_DECODER (RA_288, ra_288);
+    REGISTER_DECODER (RALF, ralf);
     REGISTER_DECODER (SHORTEN, shorten);
     REGISTER_DECODER (SIPR, sipr);
     REGISTER_DECODER (SMACKAUD, smackaud);

libavcodec/avcodec.h

@@ -383,6 +383,7 @@ enum CodecID {
     CODEC_ID_8SVX_EXP,
     CODEC_ID_8SVX_FIB,
     CODEC_ID_BMV_AUDIO,
+    CODEC_ID_RALF,
 
     /* subtitle codecs */
     CODEC_ID_FIRST_SUBTITLE = 0x17000,          ///< A dummy ID pointing at the start of subtitle codecs.

libavcodec/ralf.c

+/*
+ * RealAudio Lossless decoder
+ *
+ * Copyright (c) 2012 Konstantin Shishkov
+ *
+ * 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 2.1 of the License, or (at your option) any later version.
+ *
+ * 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * This is a decoder for Real Audio Lossless format.
+ * Dedicated to the mastermind behind it, Ralph Wiggum.
+ */
+
+#include "avcodec.h"
+#include "get_bits.h"
+#include "golomb.h"
+#include "unary.h"
+#include "libavutil/audioconvert.h"
+#include "ralfdata.h"
+
+#define FILTER_NONE 0
+#define FILTER_RAW  642
+
+typedef struct VLCSet {
+    VLC filter_params;
+    VLC bias;
+    VLC coding_mode;
+    VLC filter_coeffs[10][11];
+    VLC short_codes[15];
+    VLC long_codes[125];
+} VLCSet;
+
+#define RALF_MAX_PKT_SIZE 8192
+
+typedef struct RALFContext {
+    AVFrame frame;
+
+    int version;
+    int max_frame_size;
+    VLCSet sets[3];
+    int32_t channel_data[2][4096];
+
+    int     filter_params;   ///< combined filter parameters for the current channel data
+    int     filter_length;   ///< length of the filter for the current channel data
+    int     filter_bits;     ///< filter precision for the current channel data
+    int32_t filter[64];
+
+    int     bias[2];         ///< a constant value added to channel data after filtering
+
+    int num_blocks;          ///< number of blocks inside the frame
+    int sample_offset;
+    int block_size[1 << 12]; ///< size of the blocks
+    int block_pts[1 << 12];  ///< block start time (in milliseconds)
+
+    uint8_t pkt[16384];
+    int     has_pkt;
+} RALFContext;
+
+#define MAX_ELEMS 644 // no RALF table uses more than that
+
+static int init_ralf_vlc(VLC *vlc, const uint8_t *data, int elems)
+{
+    uint8_t  lens[MAX_ELEMS];
+    uint16_t codes[MAX_ELEMS];
+    int counts[17], prefixes[18];
+    int i, cur_len;
+    int max_bits = 0;
+    GetBitContext gb;
+
+    init_get_bits(&gb, data, elems * 4);
+
+    for (i = 0; i <= 16; i++)
+        counts[i] = 0;
+    for (i = 0; i < elems; i++) {
+        cur_len  = get_bits(&gb, 4) + 1;
+        counts[cur_len]++;
+        max_bits = FFMAX(max_bits, cur_len);
+        lens[i]  = cur_len;
+    }
+    prefixes[1] = 0;
+    for (i = 1; i <= 16; i++)
+        prefixes[i + 1] = (prefixes[i] + counts[i]) << 1;
+
+    for (i = 0; i < elems; i++)
+        codes[i] = prefixes[lens[i]]++;
+
+    return ff_init_vlc_sparse(vlc, FFMIN(max_bits, 9), elems,
+                              lens, 1, 1, codes, 2, 2, NULL, 0, 0, 0);
+}
+
+static av_cold int decode_close(AVCodecContext *avctx)
+{
+    RALFContext *ctx = avctx->priv_data;
+    int i, j, k;
+
+    for (i = 0; i < 3; i++) {
+        ff_free_vlc(&ctx->sets[i].filter_params);
+        ff_free_vlc(&ctx->sets[i].bias);
+        ff_free_vlc(&ctx->sets[i].coding_mode);
+        for (j = 0; j < 10; j++)
+            for (k = 0; k < 11; k++)
+                ff_free_vlc(&ctx->sets[i].filter_coeffs[j][k]);
+        for (j = 0; j < 15; j++)
+            ff_free_vlc(&ctx->sets[i].short_codes[j]);
+        for (j = 0; j < 125; j++)
+            ff_free_vlc(&ctx->sets[i].long_codes[j]);
+    }
+
+    return 0;
+}
+
+static av_cold int decode_init(AVCodecContext *avctx)
+{
+    RALFContext *ctx = avctx->priv_data;
+    int i, j, k;
+    int ret;
+
+    if (avctx->extradata_size < 24 || memcmp(avctx->extradata, "LSD:", 4)) {
+        av_log(avctx, AV_LOG_ERROR, "Extradata is not groovy, dude\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    ctx->version = AV_RB16(avctx->extradata + 4);
+    if (ctx->version != 0x103) {
+        av_log_ask_for_sample(avctx, "unknown version %X\n", ctx->version);
+        return AVERROR_PATCHWELCOME;
+    }
+
+    avctx->channels    = AV_RB16(avctx->extradata + 8);
+    avctx->sample_rate = AV_RB32(avctx->extradata + 12);
+    if (avctx->channels < 1 || avctx->channels > 2
+        || avctx->sample_rate < 8000 || avctx->sample_rate > 96000) {
+        av_log(avctx, AV_LOG_ERROR, "Invalid coding parameters %d Hz %d ch\n",
+               avctx->sample_rate, avctx->channels);
+        return AVERROR_INVALIDDATA;
+    }
+    avctx->sample_fmt     = AV_SAMPLE_FMT_S16;
+    avctx->channel_layout = (avctx->channels == 2) ? AV_CH_LAYOUT_STEREO
+                                                   : AV_CH_LAYOUT_MONO;
+
+    avcodec_get_frame_defaults(&ctx->frame);
+    avctx->coded_frame = &ctx->frame;
+
+    ctx->max_frame_size = AV_RB32(avctx->extradata + 16);
+    if (ctx->max_frame_size > (1 << 20) || !ctx->max_frame_size) {
+        av_log(avctx, AV_LOG_ERROR, "invalid frame size %d\n",
+               ctx->max_frame_size);
+    }
+    ctx->max_frame_size = FFMAX(ctx->max_frame_size, avctx->sample_rate);
+
+    for (i = 0; i < 3; i++) {
+        ret = init_ralf_vlc(&ctx->sets[i].filter_params, filter_param_def[i],
+                            FILTERPARAM_ELEMENTS);
+        if (ret < 0) {
+            decode_close(avctx);
+            return ret;
+        }
+        ret = init_ralf_vlc(&ctx->sets[i].bias, bias_def[i], BIAS_ELEMENTS);
+        if (ret < 0) {
+            decode_close(avctx);
+            return ret;
+        }
+        ret = init_ralf_vlc(&ctx->sets[i].coding_mode, coding_mode_def[i],
+                            CODING_MODE_ELEMENTS);
+        if (ret < 0) {
+            decode_close(avctx);
+            return ret;
+        }
+        for (j = 0; j < 10; j++) {
+            for (k = 0; k < 11; k++) {
+                ret = init_ralf_vlc(&ctx->sets[i].filter_coeffs[j][k],
+                                    filter_coeffs_def[i][j][k],
+                                    FILTER_COEFFS_ELEMENTS);
+                if (ret < 0) {
+                    decode_close(avctx);
+                    return ret;
+                }
+            }
+        }
+        for (j = 0; j < 15; j++) {
+            ret = init_ralf_vlc(&ctx->sets[i].short_codes[j],
+                                short_codes_def[i][j], SHORT_CODES_ELEMENTS);
+            if (ret < 0) {
+                decode_close(avctx);
+                return ret;
+            }
+        }
+        for (j = 0; j < 125; j++) {
+            ret = init_ralf_vlc(&ctx->sets[i].long_codes[j],
+                                long_codes_def[i][j], LONG_CODES_ELEMENTS);
+            if (ret < 0) {
+                decode_close(avctx);
+                return ret;
+            }
+        }
+    }
+
+    return 0;
+}
+
+static inline int extend_code(GetBitContext *gb, int val, int range, int bits)
+{
+    if (val == 0) {
+        val = -range - get_ue_golomb(gb);
+    } else if (val == range * 2) {
+        val =  range + get_ue_golomb(gb);
+    } else {
+        val -= range;
+    }
+    if (bits)
+        val = (val << bits) | get_bits(gb, bits);
+    return val;
+}
+
+static int decode_channel(RALFContext *ctx, GetBitContext *gb, int ch,
+                          int length, int mode, int bits)
+{
+    int i, t;
+    int code_params;
+    VLCSet *set = ctx->sets + mode;
+    VLC *code_vlc; int range, range2, add_bits;
+    int *dst = ctx->channel_data[ch];
+
+    ctx->filter_params = get_vlc2(gb, set->filter_params.table, 9, 2);
+    ctx->filter_bits   = (ctx->filter_params - 2) >> 6;
+    ctx->filter_length = ctx->filter_params - (ctx->filter_bits << 6) - 1;
+
+    if (ctx->filter_params == FILTER_RAW) {
+        for (i = 0; i < length; i++)
+            dst[i] = get_bits(gb, bits);
+        ctx->bias[ch] = 0;
+        return 0;
+    }
+
+    ctx->bias[ch] = get_vlc2(gb, set->bias.table, 9, 2);
+    ctx->bias[ch] = extend_code(gb, ctx->bias[ch], 127, 4);
+
+    if (ctx->filter_params == FILTER_NONE) {
+        memset(dst, 0, sizeof(*dst) * length);
+        return 0;
+    }
+
+    if (ctx->filter_params > 1) {
+        int cmode = 0, coeff = 0;
+        VLC *vlc = set->filter_coeffs[ctx->filter_bits] + 5;
+
+        add_bits = ctx->filter_bits;
+
+        for (i = 0; i < ctx->filter_length; i++) {
+            t = get_vlc2(gb, vlc[cmode].table, vlc[cmode].bits, 2);
+            t = extend_code(gb, t, 21, add_bits);
+            if (!cmode)
+                coeff -= 12 << add_bits;
+            coeff = t - coeff;
+            ctx->filter[i] = coeff;
+
+            cmode = coeff >> add_bits;
+            if (cmode < 0) {
+                cmode = -1 - av_log2(-cmode);
+                if (cmode < -5)
+                    cmode = -5;
+            } else if (cmode > 0) {
+                cmode =  1 + av_log2(cmode);
+                if (cmode > 5)
+                    cmode = 5;
+            }
+        }
+    }
+
+    code_params = get_vlc2(gb, set->coding_mode.table, set->coding_mode.bits, 2);
+    if (code_params >= 15) {
+        add_bits = av_clip((code_params / 5 - 3) / 2, 0, 10);
+        if (add_bits > 9 && (code_params % 5) != 2)
+            add_bits--;
+        range    = 10;
+        range2   = 21;
+        code_vlc = set->long_codes + code_params - 15;
+    } else {
+        add_bits = 0;
+        range    = 6;
+        range2   = 13;
+        code_vlc = set->short_codes + code_params;
+    }
+
+    for (i = 0; i < length; i += 2) {
+        int code1, code2;
+
+        t = get_vlc2(gb, code_vlc->table, code_vlc->bits, 2);
+        code1 = t / range2;
+        code2 = t % range2;
+        dst[i]     = extend_code(gb, code1, range, 0) << add_bits;
+        dst[i + 1] = extend_code(gb, code2, range, 0) << add_bits;
+        if (add_bits) {
+            dst[i]     |= get_bits(gb, add_bits);
+            dst[i + 1] |= get_bits(gb, add_bits);
+        }
+    }
+
+    return 0;
+}
+
+static void apply_lpc(RALFContext *ctx, int ch, int length, int bits)
+{
+    int i, j, acc;
+    int *audio = ctx->channel_data[ch];
+    int bias = 1 << (ctx->filter_bits - 1);
+    int max_clip = (1 << bits) - 1, min_clip = -max_clip - 1;
+
+    for (i = 1; i < length; i++) {
+        int flen = FFMIN(ctx->filter_length, i);
+
+        acc = 0;
+        for (j = 0; j < flen; j++)
+            acc += ctx->filter[j] * audio[i - j - 1];
+        if (acc < 0) {
+            acc = (acc + bias - 1) >> ctx->filter_bits;
+            acc = FFMAX(acc, min_clip);
+        } else {
+            acc = (acc + bias) >> ctx->filter_bits;
+            acc = FFMIN(acc, max_clip);
+        }
+        audio[i] += acc;
+    }
+}
+
+static int decode_block(AVCodecContext *avctx, GetBitContext *gb, int16_t *dst)
+{
+    RALFContext *ctx = avctx->priv_data;
+    int len, ch, ret;
+    int dmode, mode[2], bits[2];
+    int *ch0, *ch1;
+    int i, t, t2;
+
+    len = 12 - get_unary(gb, 0, 6);
+
+    if (len <= 7) len ^= 1; // codes for length = 6 and 7 are swapped
+    len = 1 << len;
+
+    if (ctx->sample_offset + len > ctx->max_frame_size) {
+        av_log(avctx, AV_LOG_ERROR,
+               "Decoder's stomach is crying, it ate too many samples\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    if (avctx->channels > 1)
+        dmode = get_bits(gb, 2) + 1;
+    else
+        dmode = 0;
+
+    mode[0] = (dmode == 4) ? 1 : 0;
+    mode[1] = (dmode >= 2) ? 2 : 0;
+    bits[0] = 16;
+    bits[1] = (mode[1] == 2) ? 17 : 16;
+
+    for (ch = 0; ch < avctx->channels; ch++) {
+        if ((ret = decode_channel(ctx, gb, ch, len, mode[ch], bits[ch])) < 0)
+            return ret;
+        if (ctx->filter_params > 1 && ctx->filter_params != FILTER_RAW) {
+            ctx->filter_bits += 3;
+            apply_lpc(ctx, ch, len, bits[ch]);
+        }
+        if (get_bits_left(gb) < 0)
+            return AVERROR_INVALIDDATA;
+    }
+    ch0 = ctx->channel_data[0];
+    ch1 = ctx->channel_data[1];
+    switch (dmode) {
+    case 0:
+        for (i = 0; i < len; i++)
+            *dst++ = ch0[i] + ctx->bias[0];
+        break;
+    case 1:
+        for (i = 0; i < len; i++) {
+            *dst++ = ch0[i] + ctx->bias[0];
+            *dst++ = ch1[i] + ctx->bias[1];
+        }
+        break;
+    case 2:
+        for (i = 0; i < len; i++) {
+            ch0[i] += ctx->bias[0];
+            *dst++ = ch0[i];
+            *dst++ = ch0[i] - (ch1[i] + ctx->bias[1]);
+        }
+        break;
+    case 3:
+        for (i = 0; i < len; i++) {
+            t  = ch0[i] + ctx->bias[0];
+            t2 = ch1[i] + ctx->bias[1];
+            *dst++ = t + t2;
+            *dst++ = t;
+        }
+        break;
+    case 4:
+        for (i = 0; i < len; i++) {
+            t  =   ch1[i] + ctx->bias[1];
+            t2 = ((ch0[i] + ctx->bias[0]) << 1) | (t & 1);
+            *dst++ = (t2 + t) / 2;
+            *dst++ = (t2 - t) / 2;
+        }
+        break;
+    }
+
+    ctx->sample_offset += len;
+
+    return 0;
+}
+
+static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr,
+                        AVPacket *avpkt)
+{
+    RALFContext *ctx = avctx->priv_data;
+    int16_t *samples;
+    int ret;
+    GetBitContext gb;
+    int table_size, table_bytes, i;
+    const uint8_t *src, *block_pointer;
+    int src_size;
+    int bytes_left;
+
+    if (ctx->has_pkt) {
+        ctx->has_pkt = 0;
+        table_bytes = (AV_RB16(avpkt->data) + 7) >> 3;
+        if (table_bytes + 3 > avpkt->size || avpkt->size > RALF_MAX_PKT_SIZE) {
+            av_log(avctx, AV_LOG_ERROR, "Wrong packet's breath smells of wrong data!\n");
+            return AVERROR_INVALIDDATA;
+        }
+        if (memcmp(ctx->pkt, avpkt->data, 2 + table_bytes)) {
+            av_log(avctx, AV_LOG_ERROR, "Wrong packet tails are wrong!\n");
+            return AVERROR_INVALIDDATA;
+        }
+
+        src      = ctx->pkt;
+        src_size = RALF_MAX_PKT_SIZE + avpkt->size;
+        memcpy(ctx->pkt + RALF_MAX_PKT_SIZE, avpkt->data + 2 + table_bytes,
+               avpkt->size - 2 - table_bytes);
+    } else {
+        if (avpkt->size == RALF_MAX_PKT_SIZE) {
+            memcpy(ctx->pkt, avpkt->data, avpkt->size);
+            ctx->has_pkt   = 1;
+            *got_frame_ptr = 0;
+
+            return avpkt->size;
+        }
+        src      = avpkt->data;
+        src_size = avpkt->size;
+    }
+
+    ctx->frame.nb_samples = ctx->max_frame_size;
+    if ((ret = avctx->get_buffer(avctx, &ctx->frame)) < 0) {
+        av_log(avctx, AV_LOG_ERROR, "Me fail get_buffer()? That's unpossible!\n");
+        return ret;
+    }
+    samples = (int16_t*)ctx->frame.data[0];
+
+    if (src_size < 5) {
+        av_log(avctx, AV_LOG_ERROR, "too short packets are too short!\n");
+        return AVERROR_INVALIDDATA;
+    }
+    table_size  = AV_RB16(src);
+    table_bytes = (table_size + 7) >> 3;
+    if (src_size < table_bytes + 3) {
+        av_log(avctx, AV_LOG_ERROR, "short packets are short!\n");
+        return AVERROR_INVALIDDATA;
+    }
+    init_get_bits(&gb, src + 2, table_size);
+    ctx->num_blocks = 0;
+    while (get_bits_left(&gb) > 0) {
+        ctx->block_size[ctx->num_blocks] = get_bits(&gb, 15);
+        if (get_bits1(&gb)) {
+            ctx->block_pts[ctx->num_blocks] = get_bits(&gb, 9);
+        } else {
+            ctx->block_pts[ctx->num_blocks] = 0;
+        }
+        ctx->num_blocks++;
+    }
+
+    block_pointer = src      + table_bytes + 2;
+    bytes_left    = src_size - table_bytes - 2;
+    ctx->sample_offset = 0;
+    for (i = 0; i < ctx->num_blocks; i++) {
+        if (bytes_left < ctx->block_size[i]) {
+            av_log(avctx, AV_LOG_ERROR, "I'm pedaling backwards\n");
+            break;
+        }
+        init_get_bits(&gb, block_pointer, ctx->block_size[i] * 8);
+        if (decode_block(avctx, &gb, samples + ctx->sample_offset
+                                               * avctx->channels) < 0) {
+            av_log(avctx, AV_LOG_ERROR, "Sir, I got carsick in your office. Not decoding the rest of packet.\n");
+            break;
+        }
+        block_pointer += ctx->block_size[i];
+        bytes_left    -= ctx->block_size[i];
+    }
+
+    ctx->frame.nb_samples = ctx->sample_offset;
+    *got_frame_ptr  = ctx->sample_offset > 0;
+    *(AVFrame*)data = ctx->frame;
+
+    return avpkt->size;
+}
+
+static void decode_flush(AVCodecContext *avctx)
+{
+    RALFContext *ctx = avctx->priv_data;
+
+    ctx->has_pkt = 0;
+}
+
+
+AVCodec ff_ralf_decoder = {
+    .name           = "ralf",
+    .type           = AVMEDIA_TYPE_AUDIO,
+    .id             = CODEC_ID_RALF,
+    .priv_data_size = sizeof(RALFContext),
+    .init           = decode_init,
+    .close          = decode_close,
+    .decode         = decode_frame,
+    .flush          = decode_flush,
+    .capabilities   = CODEC_CAP_DR1,
+    .long_name      = NULL_IF_CONFIG_SMALL("RealAudio Lossless")
+};

libavcodec/version.h

@@ -21,7 +21,7 @@
 #define AVCODEC_VERSION_H
 
 #define LIBAVCODEC_VERSION_MAJOR 54
-#define LIBAVCODEC_VERSION_MINOR  9
+#define LIBAVCODEC_VERSION_MINOR 10
 #define LIBAVCODEC_VERSION_MICRO  0
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \

libavformat/rm.c

@@ -42,5 +42,6 @@ const AVCodecTag ff_rm_codec_tags[] = {
     { CODEC_ID_SIPR,   MKTAG('s','i','p','r') },
     { CODEC_ID_AAC,    MKTAG('r','a','a','c') },
     { CODEC_ID_AAC,    MKTAG('r','a','c','p') },
+    { CODEC_ID_RALF,   MKTAG('L','S','D',':') },
     { CODEC_ID_NONE },
 };

libavformat/rmdec.c

@@ -310,6 +310,15 @@ ff_rm_read_mdpr_codecdata (AVFormatContext *s, AVIOContext *pb,
         /* ra type header */
         if (rm_read_audio_stream_info(s, pb, st, rst, 0))
             return -1;
+    } else if (v == MKBETAG('L', 'S', 'D', ':')) {
+        avio_seek(pb, -4, SEEK_CUR);
+        if ((ret = rm_read_extradata(pb, st->codec, codec_data_size)) < 0)
+            return ret;
+
+        st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
+        st->codec->codec_tag  = AV_RL32(st->codec->extradata);
+        st->codec->codec_id   = ff_codec_get_id(ff_rm_codec_tags,
+                                                st->codec->codec_tag);
     } else {
         int fps;
         if (avio_rl32(pb) != MKTAG('V', 'I', 'D', 'O')) {