[MPlayer-dev-eng] Re: [PATCH] encoding audio with libavcodec
Tobias Diedrich
ranma at gmx.at
Sun Nov 2 06:30:48 CET 2003
Nico wrote:
> Daniele Forghieri and I have developed this patch to use Lavc audio
> codecs during encoding.
Nice :-)
I looked over it and made a few modifications.
It now initializes lavc first and uses alavc_ctx->frame_size and
alavc_ctx->block_align to set mux_a->wf->nBlockAlign.
cbSize has to be 12 (sizeof(waveformat-mpeglayer3waveformat)), or the
extension is ignored (which it is anyway if the codec is not mp3).
I changed the default bitrate to 224 because IMHO 128 is quite low for
mp2. adpcm_ima_wav almost works.
--
Tobias PGP: http://9ac7e0bc.2ya.com
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-------------- next part --------------
Index: mencoder.c
===================================================================
RCS file: /cvsroot/mplayer/main/mencoder.c,v
retrieving revision 1.219
diff -u -r1.219 mencoder.c
--- mencoder.c 22 Oct 2003 17:04:15 -0000 1.219
+++ mencoder.c 2 Nov 2003 05:22:58 -0000
@@ -14,6 +14,7 @@
#define ACODEC_PCM 1
#define ACODEC_VBRMP3 2
#define ACODEC_NULL 3
+#define ACODEC_LAVC 4
#include <stdio.h>
#include <stdlib.h>
@@ -71,6 +72,21 @@
#include "osdep/timer.h"
+#ifdef USE_LIBAVCODEC
+// for lavc audio encoding
+#include "libavcodec/avcodec.h"
+AVCodec *alavc_codec;
+AVCodecContext *alavc_ctx = NULL;
+static char *alavc_param_codec = "mp2";
+static int alavc_param_bitrate = 224;
+static int alavc_ok = 0;
+static uint16_t alavc_codec_tag = 0x0;
+// tmp buffer for lavc audio encoding (to free!!!!!)
+void *alavc_buf = NULL;
+
+uint32_t alavc_find_tag(char *codec);
+#endif
+
int vo_doublebuffering=0;
int vo_directrendering=0;
int vo_config_count=0;
@@ -792,6 +808,101 @@
}
break;
#endif
+#ifdef USE_LIBAVCODEC
+case ACODEC_LAVC:
+ if(! alavc_param_codec)
+ {
+ mp_msg(MSGT_MENCODER, MSGL_FATAL, "Audio LAVC, Missing codec name!\n");
+ exit(1);
+ }
+ avcodec_init();
+ avcodec_register_all();
+
+ alavc_codec = avcodec_find_encoder_by_name(alavc_param_codec);
+ if (!alavc_codec)
+ {
+ mp_msg(MSGT_MENCODER, MSGL_FATAL, "Audio LAVC, couldn't find encoder for codec %s\n", alavc_param_codec);
+ break;
+ }
+
+ alavc_ctx = avcodec_alloc_context();
+ if(alavc_ctx == NULL)
+ {
+ mp_msg(MSGT_MENCODER, MSGL_FATAL, "Audio LAVC, couldn't allocate context!\n");
+ break;
+ }
+
+ // put sample parameters
+ alavc_ctx->bit_rate = alavc_param_bitrate * 1000;
+ alavc_ctx->channels = audio_output_channels ? audio_output_channels : sh_audio->channels;
+ alavc_ctx->sample_rate = force_srate ? force_srate : sh_audio->samplerate;
+
+ if(avcodec_open(alavc_ctx, alavc_codec) < 0)
+ {
+ mp_msg(MSGT_MENCODER, MSGL_FATAL, "Couldn't open codec %s, br=%d\n", alavc_param_codec, alavc_param_bitrate);
+ break;
+ }
+
+ alavc_buf = malloc(alavc_ctx->frame_size * 2 * alavc_ctx->channels);
+ if(alavc_buf == NULL)
+ {
+ fprintf(stderr, "Couldn't allocate %d bytes\n", alavc_ctx->frame_size * 2 * alavc_ctx->channels);
+ break;
+ }
+
+ alavc_ok = 1;
+
+ mux_a->h.dwSampleSize = 1;
+ mux_a->h.dwRate = (1000 * alavc_param_bitrate / 8);
+ mux_a->h.dwScale = 1;
+
+ if (sizeof(MPEGLAYER3WAVEFORMAT) != 30)
+ mp_msg(MSGT_MENCODER, MSGL_WARN,
+ "sizeof(MPEGLAYER3WAVEFORMAT)==%d!=30, maybe broken C compiler?\n",
+ sizeof(MPEGLAYER3WAVEFORMAT));
+
+ mux_a->wf = malloc(sizeof(MPEGLAYER3WAVEFORMAT)); // should be 30
+
+ mux_a->wf->nChannels = alavc_ctx->channels;
+ mux_a->wf->nSamplesPerSec = alavc_ctx->sample_rate;
+ mux_a->wf->nAvgBytesPerSec = (1000 * alavc_param_bitrate / 8);
+ if (alavc_ctx->block_align)
+ mux_a->wf->nBlockAlign = alavc_ctx->block_align;
+ else
+ mux_a->wf->nBlockAlign = alavc_ctx->frame_size;
+ mux_a->wf->wBitsPerSample = 0;
+ mux_a->wf->cbSize = 12;
+
+ ((MPEGLAYER3WAVEFORMAT *) (mux_a->wf))->wID = 1;
+ ((MPEGLAYER3WAVEFORMAT *) (mux_a->wf))->fdwFlags = 2;
+ ((MPEGLAYER3WAVEFORMAT *) (mux_a->wf))->nBlockSize = mux_a->wf->nAvgBytesPerSec * mux_a->wf->nBlockAlign / mux_a->wf->nSamplesPerSec;
+ ((MPEGLAYER3WAVEFORMAT *) (mux_a->wf))->nFramesPerBlock = 1;
+ ((MPEGLAYER3WAVEFORMAT *) (mux_a->wf))->nCodecDelay = 0;
+
+ if(alavc_codec_tag != 0)
+ mux_a->wf->wFormatTag = alavc_codec_tag;
+ else
+ mux_a->wf->wFormatTag = alavc_find_tag(alavc_param_codec);
+
+ // setup filter:
+ if (!init_audio_filters(
+ sh_audio,
+ sh_audio->samplerate, sh_audio->channels,
+ sh_audio->sample_format, sh_audio->samplesize,
+ mux_a->wf->nSamplesPerSec, mux_a->wf->nChannels,
+#ifdef WORDS_BIGENDIAN
+ AFMT_S16_BE, 2,
+#else
+ AFMT_S16_LE, 2,
+#endif
+ alavc_ctx->frame_size, mux_a->h.dwRate * mux_a->wf->nChannels * 2)) {
+ mp_msg(MSGT_CPLAYER, MSGL_ERR, "Couldn't find matching filter / ao format!\n");
+ }
+
+ mp_msg(MSGT_MENCODER, MSGL_V, "FRAME_SIZE: %d, BUFFER_SIZE: %d, TAG: 0x%x\n", alavc_ctx->frame_size, alavc_ctx->frame_size * 2 * alavc_ctx->channels, mux_a->wf->wFormatTag);
+
+ break;
+#endif
}
if (verbose>1) print_wave_header(mux_a->wf);
@@ -932,6 +1043,25 @@
len=mux_a->h.dwSampleSize*(mux_a->h.dwRate/audio_density);
len=dec_audio(sh_audio,mux_a->buffer,len);
break;
+#ifdef USE_LIBAVCODEC
+ case ACODEC_LAVC:
+ {
+ if(alavc_ok)
+ {
+ int size, rd_len;
+
+ size = alavc_ctx->frame_size * 2 * mux_a->wf->nChannels;
+
+ rd_len = dec_audio(sh_audio, alavc_buf, size);
+ if(rd_len != size)
+ break;
+
+ // Encode one frame
+ len = avcodec_encode_audio(alavc_ctx, &(mux_a->buffer[0]), size, alavc_buf);
+ }
+ }
+ break;
+#endif
}
} else {
// VBR - encode/copy an audio frame
@@ -1294,6 +1424,11 @@
if(demuxer) free_demuxer(demuxer);
if(stream) free_stream(stream); // kill cache thread
+#ifdef USE_LIBAVCODEC
+if(alavc_buf != NULL)
+ free(alavc_buf);
+#endif
+
return interrupted;
}
@@ -1600,3 +1735,20 @@
mencoder_exit(0, NULL);
}
#endif
+
+#ifdef USE_LIBAVCODEC
+uint32_t alavc_find_tag(char *codec)
+{
+ if(codec == NULL)
+ return 0;
+
+ if(! strcasecmp(codec, "mp2"))
+ return 0x50;
+
+ if(! strcasecmp(codec, "ac3"))
+ return 0x2000;
+
+ return 0;
+}
+#endif
+
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