[FFmpeg-devel] [PATCH]CAF muxer

Carl Eugen Hoyos cehoyos at ag.or.at
Sun May 8 21:11:02 CEST 2011


Hi!

Attached is a preliminary caf muxer, it only works for PCM and similar simple 
codecs.
(aif uses "CHAN")

Please comment, Carl Eugen
-------------- next part --------------
diff --git a/libavformat/Makefile b/libavformat/Makefile
index 739decf..26c094c 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -48,6 +48,7 @@ OBJS-$(CONFIG_BFI_DEMUXER)               += bfi.o
 OBJS-$(CONFIG_BINK_DEMUXER)              += bink.o
 OBJS-$(CONFIG_C93_DEMUXER)               += c93.o vocdec.o voc.o
 OBJS-$(CONFIG_CAF_DEMUXER)               += cafdec.o caf.o mov.o riff.o isom.o
+OBJS-$(CONFIG_CAF_MUXER)                 += cafenc.o caf.o riff.o isom.o
 OBJS-$(CONFIG_CAVSVIDEO_DEMUXER)         += cavsvideodec.o rawdec.o
 OBJS-$(CONFIG_CAVSVIDEO_MUXER)           += rawenc.o
 OBJS-$(CONFIG_CDG_DEMUXER)               += cdg.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index d08f2f7..a9fa117 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -71,7 +71,7 @@ void av_register_all(void)
     REGISTER_DEMUXER  (BFI, bfi);
     REGISTER_DEMUXER  (BINK, bink);
     REGISTER_DEMUXER  (C93, c93);
-    REGISTER_DEMUXER  (CAF, caf);
+    REGISTER_MUXDEMUX (CAF, caf);
     REGISTER_MUXDEMUX (CAVSVIDEO, cavsvideo);
     REGISTER_DEMUXER  (CDG, cdg);
     REGISTER_MUXER    (CRC, crc);
diff --git a/libavformat/caf.c b/libavformat/caf.c
index fd91674..dcffa34 100644
--- a/libavformat/caf.c
+++ b/libavformat/caf.c
@@ -39,6 +39,7 @@ const AVCodecTag ff_codec_caf_tags[] = {
   /*{ CODEC_ID_DVAUDIO,         MKBETAG('v','d','v','a') },*/
   /*{ CODEC_ID_DVAUDIO,         MKBETAG('d','v','c','a') },*/
     { CODEC_ID_ADPCM_IMA_QT,    MKBETAG('i','m','a','4') },
+    { CODEC_ID_GSM,             MKBETAG('a','g','s','m') },
     { CODEC_ID_MACE3,           MKBETAG('M','A','C','3') },
     { CODEC_ID_MACE6,           MKBETAG('M','A','C','6') },
     { CODEC_ID_MP3,             MKBETAG('.','m','p','3') },
@@ -54,6 +55,17 @@ const AVCodecTag ff_codec_caf_tags[] = {
   /*{ MPEG4CELP                 MKBETAG('c','e','l','p') },*/
   /*{ MPEG4HVXC                 MKBETAG('h','v','x','c') },*/
   /*{ MPEG4TwinVQ               MKBETAG('t','w','v','q') },*/
+  /* only used for encoding: */
+    { CODEC_ID_PCM_S16LE,       MKBETAG('l','p','c','m') },
+    { CODEC_ID_PCM_S16BE,       MKBETAG('l','p','c','m') },
+    { CODEC_ID_PCM_S24LE,       MKBETAG('l','p','c','m') },
+    { CODEC_ID_PCM_S24BE,       MKBETAG('l','p','c','m') },
+    { CODEC_ID_PCM_S32LE,       MKBETAG('l','p','c','m') },
+    { CODEC_ID_PCM_S32BE,       MKBETAG('l','p','c','m') },
+    { CODEC_ID_PCM_F32LE,       MKBETAG('l','p','c','m') },
+    { CODEC_ID_PCM_F32BE,       MKBETAG('l','p','c','m') },
+    { CODEC_ID_PCM_F64LE,       MKBETAG('l','p','c','m') },
+    { CODEC_ID_PCM_F64BE,       MKBETAG('l','p','c','m') },
     { CODEC_ID_NONE,            0 },
 };
 
diff --git a/libavformat/isom.c b/libavformat/isom.c
index 76a7082..5b68859 100644
--- a/libavformat/isom.c
+++ b/libavformat/isom.c
@@ -27,6 +27,7 @@
 #include "internal.h"
 #include "isom.h"
 #include "riff.h"
+#include "avio_internal.h"
 #include "libavcodec/mpeg4audio.h"
 #include "libavcodec/mpegaudiodata.h"
 
@@ -480,3 +481,31 @@ void ff_mov_read_chan(AVFormatContext *s, int64_t size, AVCodecContext *codec)
     avio_skip(pb, 8);
 }
 
+void ff_mov_write_chan(AVFormatContext *s, int64_t channel_layout,
+                       const char *chunk_type)
+{
+    AVIOContext *pb = s->pb;
+    const MovChannelLayout *layouts;
+    uint32_t layout_tag = 0;
+
+    if (!channel_layout)
+        return;
+
+    for (layouts = mov_channel_layout; layouts->channel_layout; layouts++)
+        if (channel_layout == layouts->channel_layout) {
+            layout_tag = layouts->layout_tag;
+            break;
+        }
+
+    ffio_wfourcc(pb, chunk_type);
+    avio_wb64(pb, 12);             //< mChunkSize
+    if (layout_tag) {
+        avio_wb32(pb, layout_tag); //< mChannelLayoutTag
+        avio_wb32(pb, 0);          //< mChannelBitmap
+    } else {
+        avio_wb32(pb, 0x10000);    //< kCAFChannelLayoutTag_UseChannelBitmap
+        avio_wb32(pb, channel_layout);
+    }
+    avio_wb32(pb, 0);              //< mNumberChannelDescriptions
+}
+
diff --git a/libavformat/isom.h b/libavformat/isom.h
index 081d227..83e472a 100644
--- a/libavformat/isom.h
+++ b/libavformat/isom.h
@@ -157,5 +157,7 @@ enum CodecID ff_mov_get_lpcm_codec_id(int bps, int flags);
 
 int ff_mov_read_stsd_entries(MOVContext *c, AVIOContext *pb, int entries);
 void ff_mov_read_chan(AVFormatContext *s, int64_t size, AVCodecContext *codec);
+void ff_mov_write_chan(AVFormatContext *s, int64_t channel_layout,
+                       const char *chunk_type);
 
 #endif /* AVFORMAT_ISOM_H */
--- /dev/null	2009-12-16 00:58:22.000000000 +0100
+++ libavformat/cafenc.c	2011-05-08 20:50:24.366735853 +0200
@@ -0,0 +1,144 @@
+/*
+ * Core Audio Format muxer
+ * Copyright (c) 2011 Carl Eugen Hoyos
+ *
+ * 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 "avformat.h"
+#include "caf.h"
+#include "riff.h"
+#include "isom.h"
+#include "avio_internal.h"
+
+typedef struct {
+    int64_t data;
+} CAFContext;
+
+static uint32_t codec_flags(enum CodecID codec_id) {
+    switch (codec_id) {
+    case CODEC_ID_PCM_F32BE:
+    case CODEC_ID_PCM_F64BE:
+        return 1; //< kCAFLinearPCMFormatFlagIsFloat
+    case CODEC_ID_PCM_S16LE:
+    case CODEC_ID_PCM_S24LE:
+    case CODEC_ID_PCM_S32LE:
+        return 2; //< kCAFLinearPCMFormatFlagIsLittleEndian
+    case CODEC_ID_PCM_F32LE:
+    case CODEC_ID_PCM_F64LE:
+        return 3; //< kCAFLinearPCMFormatFlagIsFloat | kCAFLinearPCMFormatFlagIsLittleEndian
+    default:
+        return 0;
+    }
+}
+
+static uint32_t frames_per_packet(enum CodecID codec_id) {
+    switch (codec_id) {
+    case CODEC_ID_PCM_S16LE:
+    case CODEC_ID_PCM_S16BE:
+    case CODEC_ID_PCM_S24LE:
+    case CODEC_ID_PCM_S24BE:
+    case CODEC_ID_PCM_S32LE:
+    case CODEC_ID_PCM_S32BE:
+    case CODEC_ID_PCM_F32LE:
+    case CODEC_ID_PCM_F32BE:
+    case CODEC_ID_PCM_F64LE:
+    case CODEC_ID_PCM_F64BE:
+    case CODEC_ID_PCM_ALAW:
+    case CODEC_ID_PCM_MULAW:
+        return 1;
+    case CODEC_ID_MACE3:
+    case CODEC_ID_MACE6:
+        return 6;
+    case CODEC_ID_ADPCM_IMA_QT:
+        return 64;
+    case CODEC_ID_GSM:
+        // FIXME: Is this correct?
+        return 160;
+    case CODEC_ID_QDM2:
+        return 4096;
+    default:
+        return 0;
+    }
+}
+
+static int caf_write_header(AVFormatContext *s)
+{
+    AVIOContext *pb = s->pb;
+    AVCodecContext *enc = s->streams[0]->codec;
+    CAFContext *caf = s->priv_data;
+
+    ffio_wfourcc(pb, "caff"); //< mFileType
+    avio_wb16(pb, 1);         //< mFileVersion
+    avio_wb16(pb, 0);         //< mFileFlags
+
+    ffio_wfourcc(pb, "desc");                        //< Audio Description chunk
+    avio_wb64(pb, 32);                               //< mChunkSize
+    avio_wb64(pb, av_dbl2int(enc->sample_rate));     //< mSampleRate
+    avio_wb32(pb, ff_codec_get_tag(ff_codec_caf_tags, enc->codec_id)); //< mFormatID
+    avio_wb32(pb, codec_flags(enc->codec_id));       //< mFormatFlags
+    avio_wb32(pb, enc->block_align);                 //< mBytesPerPacket
+    avio_wb32(pb, frames_per_packet(enc->codec_id)); //< mFramesPerPacket
+    avio_wb32(pb, enc->channels);                    //< mChannelsPerFrame
+    avio_wb32(pb, enc->bits_per_coded_sample);       //< mBitsPerChannel
+
+    ff_mov_write_chan(s, enc->channel_layout, "chan");
+
+    ffio_wfourcc(pb, "data"); //< Audio Data chunk
+    caf->data = avio_tell(pb);
+    avio_wb64(pb, -1);        //< mChunkSize
+    avio_wb32(pb, 0);         //< mEditCount
+
+    avio_flush(pb);
+    return 0;
+}
+
+static int caf_write_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    avio_write(s->pb, pkt->data, pkt->size);
+    return 0;
+}
+
+static int caf_write_trailer(AVFormatContext *s)
+{
+    AVIOContext *pb = s->pb;
+
+    if (pb->seekable) {
+        CAFContext *caf = s->priv_data;
+        int64_t file_size = avio_tell(pb);
+
+        avio_seek(pb, caf->data, SEEK_SET);
+        avio_wb64(pb, file_size - caf->data - 8);
+        avio_seek(pb, file_size, SEEK_SET);
+        avio_flush(pb);
+    }
+    return 0;
+}
+
+AVOutputFormat ff_caf_muxer = {
+    "caf",
+    NULL_IF_CONFIG_SMALL("Apple Core Audio Format"),
+    "audio/x-caf",
+    "caf",
+    sizeof(CAFContext),
+    CODEC_ID_PCM_S16BE,
+    CODEC_ID_NONE,
+    caf_write_header,
+    caf_write_packet,
+    caf_write_trailer,
+    .codec_tag= (const AVCodecTag* const []){ff_codec_caf_tags, 0},
+};


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