ref: c9c9adbd237fabe718fe5a92327da16e451e80cf
parent: 0fbe4e814178377435fd94bb67e4c0793352cd4d
author: rrt <rrt>
date: Sat Apr 14 13:27:32 EDT 2007
Add ffmpeg.c, oops! Add a note about video files and other audio formats to the man page.
--- a/sox.1
+++ b/sox.1
@@ -904,7 +904,10 @@
This is a pseudo-type that forces ffmpeg to be used. At the moment,
ffmpeg support is read-only. The actual file type is deduced from the
file. This pseudo-type depends on SoX having been built with optional
-ffmpeg support.
+ffmpeg support. It can read a wide range of audio files, not all of
+which are documented here, and also the audio track of many video
+files (including AVI, WMV and MPEG). At present only the first audio
+track of a file can be read.
.TP
.B .flac (also with \-t sndfile)
Free Lossless Audio CODEC compressed audio.
--- /dev/null
+++ b/src/ffmpeg.c
@@ -1,0 +1,275 @@
+/*
+ * libSoX ffmpeg formats.
+ *
+ * Copyright 2007 Reuben Thomas <rrt@sc3d.org>
+ *
+ * Based on ffplay.c Copyright 2003 Fabrice Bellard
+ *
+ * This library 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.
+ *
+ * This library 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, Fifth Floor, 51 Franklin Street, Boston, MA 02111-1301,
+ * USA. */
+
+#include "sox_i.h"
+
+#ifdef HAVE_LIBAVFORMAT
+
+#include <assert.h>
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#include <ffmpeg/avformat.h>
+
+/* Private data for ffmpeg files */
+typedef struct ffmpeg
+{+ uint8_t *audio_buf;
+ int audio_index;
+ int audio_stream;
+ AVStream *audio_st;
+ AVFormatContext *ic;
+ int audio_buf_index;
+ int audio_buf_size;
+ AVPacket audio_pkt;
+ uint8_t *audio_pkt_data;
+ int audio_pkt_size;
+} *ffmpeg_t;
+
+assert_static(sizeof(struct ffmpeg) <= SOX_MAX_FILE_PRIVSIZE,
+ /* else */ ffmpeg_PRIVSIZE_too_big);
+
+/* open a given stream. Return 0 if OK */
+static int stream_component_open(ffmpeg_t ffmpeg, int stream_index)
+{+ AVFormatContext *ic = ffmpeg->ic;
+ AVCodecContext *enc;
+ AVCodec *codec;
+
+ if (stream_index < 0 || stream_index >= (int)(ic->nb_streams))
+ return -1;
+ enc = ic->streams[stream_index]->codec;
+
+ /* hack for AC3. XXX: suppress that */
+ if (enc->channels > 2)
+ enc->channels = 2;
+
+ codec = avcodec_find_decoder(enc->codec_id);
+ enc->workaround_bugs = 1;
+ enc->error_resilience= 1;
+ if (!codec || avcodec_open(enc, codec) < 0)
+ return -1;
+ if (enc->codec_type != CODEC_TYPE_AUDIO) {+ sox_fail("ffmpeg CODEC %x is not an audio CODEC", enc->codec_type);+ return -1;
+ }
+
+ ffmpeg->audio_stream = stream_index;
+ ffmpeg->audio_st = ic->streams[stream_index];
+ ffmpeg->audio_buf_size = 0;
+ ffmpeg->audio_buf_index = 0;
+
+ memset(&ffmpeg->audio_pkt, 0, sizeof(ffmpeg->audio_pkt));
+
+ return 0;
+}
+
+static void stream_component_close(ffmpeg_t ffmpeg, int stream_index)
+{+ AVFormatContext *ic = ffmpeg->ic;
+ AVCodecContext *enc;
+
+ if (stream_index < 0 || stream_index >= (int)ic->nb_streams)
+ return;
+ enc = ic->streams[stream_index]->codec;
+
+ avcodec_close(enc);
+}
+
+/* decode one audio frame and returns its uncompressed size */
+static int audio_decode_frame(ffmpeg_t ffmpeg, uint8_t *audio_buf, int buf_size)
+{+ AVPacket *pkt = &ffmpeg->audio_pkt;
+ int len1, data_size;
+
+ for(;;) {+ /* NOTE: the audio packet can contain several frames */
+ while (ffmpeg->audio_pkt_size > 0) {+ data_size = buf_size;
+ len1 = avcodec_decode_audio2(ffmpeg->audio_st->codec,
+ (int16_t *)audio_buf, &data_size,
+ ffmpeg->audio_pkt_data, ffmpeg->audio_pkt_size);
+ if (len1 < 0) {+ /* if error, we skip the frame */
+ ffmpeg->audio_pkt_size = 0;
+ break;
+ }
+
+ ffmpeg->audio_pkt_data += len1;
+ ffmpeg->audio_pkt_size -= len1;
+ if (data_size <= 0)
+ continue;
+ return data_size;
+ }
+
+ ffmpeg->audio_pkt_data = pkt->data;
+ ffmpeg->audio_pkt_size = pkt->size;
+ }
+}
+
+/*
+ * Open file in ffmpeg.
+ */
+static int sox_ffmpeg_startread(ft_t ft)
+{+ ffmpeg_t ffmpeg = (ffmpeg_t)ft->priv;
+ AVFormatParameters params;
+ int ret;
+ unsigned i;
+
+ ffmpeg->audio_buf = xcalloc(1, AVCODEC_MAX_AUDIO_FRAME_SIZE);
+
+ /* Signal audio stream not found */
+ ffmpeg->audio_index = -1;
+
+ /* register all CODECs, demux and protocols */
+ av_register_all();
+
+ /* Open file and get format */
+ memset(¶ms, 0, sizeof(params));
+ if ((ret = av_open_input_file(&ffmpeg->ic, ft->filename, NULL, 0, ¶ms)) < 0) {+ sox_fail("ffmpeg cannot open file for reading: %s (code %d)", ft->filename, ret);+ return SOX_EOF;
+ }
+
+ /* Get CODEC parameters */
+ if ((ret = av_find_stream_info(ffmpeg->ic)) < 0) {+ sox_fail("ffmpeg could not find CODEC parameters for %s", ft->filename);+ return SOX_EOF;
+ }
+
+ /* Now we can begin to play (RTSP stream only) */
+ av_read_play(ffmpeg->ic);
+
+ /* Find audio stream (assume we're using the first) */
+ for (i = 0; i < ffmpeg->ic->nb_streams; i++) {+ AVCodecContext *enc = ffmpeg->ic->streams[i]->codec;
+ if (enc->codec_type == CODEC_TYPE_AUDIO && ffmpeg->audio_index < 0) {+ ffmpeg->audio_index = i;
+ break;
+ }
+ }
+
+ /* Open the stream */
+ if (ffmpeg->audio_index < 0 ||
+ stream_component_open(ffmpeg, ffmpeg->audio_index) < 0 ||
+ ffmpeg->audio_stream < 0) {+ sox_fail("could not open CODECs for %s", ft->filename);+ return SOX_EOF;
+ }
+
+ /* Copy format info */
+ ft->signal.rate = ffmpeg->audio_st->codec->sample_rate;
+ ft->signal.size = SOX_SIZE_16BIT;
+ ft->signal.encoding = SOX_ENCODING_SIGN2;
+ ft->signal.channels = ffmpeg->audio_st->codec->channels;
+ ft->length = 0; /* Currently we can't seek; no idea how to get this
+ info from ffmpeg anyway (in time, yes, but not in
+ samples); but ffmpeg *can* seek */
+
+ return SOX_SUCCESS;
+}
+
+/*
+ * Read up to len samples of type sox_sample_t from file into buf[].
+ * Return number of samples read.
+ */
+static sox_size_t sox_ffmpeg_read(ft_t ft, sox_ssample_t *buf, sox_size_t len)
+{+ ffmpeg_t ffmpeg = (ffmpeg_t)ft->priv;
+ AVPacket *pkt = &ffmpeg->audio_pkt;
+ int ret;
+ sox_size_t nsamp = 0, nextra;
+
+ /* Read data repeatedly until buf is full or no more can be read */
+ do {+ /* If buffer empty, read more data */
+ if (ffmpeg->audio_buf_index * 2 >= ffmpeg->audio_buf_size) {+ if ((ret = av_read_frame(ffmpeg->ic, pkt)) < 0)
+ break;
+ ffmpeg->audio_buf_size = audio_decode_frame(ffmpeg, ffmpeg->audio_buf, AVCODEC_MAX_AUDIO_FRAME_SIZE);
+ ffmpeg->audio_buf_index = 0;
+ }
+
+ nextra = min((ffmpeg->audio_buf_size - ffmpeg->audio_buf_index) / 2, (int)(len - nsamp));
+ for (; nextra > 0; nextra--)
+ buf[nsamp++] = SOX_SIGNED_16BIT_TO_SAMPLE(((int16_t *)ffmpeg->audio_buf)[ffmpeg->audio_buf_index++],);
+ } while (nsamp < len && nextra > 0);
+
+ return nsamp;
+}
+
+/*
+ * Close file for ffmpeg (this doesn't close the file handle)
+ */
+static int sox_ffmpeg_stopread(ft_t ft)
+{+ ffmpeg_t ffmpeg = (ffmpeg_t)ft->priv;
+
+ if (ffmpeg->audio_stream >= 0)
+ stream_component_close(ffmpeg, ffmpeg->audio_stream);
+ if (ffmpeg->ic) {+ av_close_input_file(ffmpeg->ic);
+ ffmpeg->ic = NULL; /* safety */
+ }
+
+ return SOX_SUCCESS;
+}
+
+static int sox_ffmpeg_startwrite(ft_t ft)
+{+ (void)ft;
+ sox_fail("Cannot (yet) write with ffmpeg");+ return SOX_EOF;
+}
+
+/* Format file suffixes */
+/* For now, comment out formats built in to SoX */
+static const char *names[] = {+ "ffmpeg", /* special type to force use of ffmpeg */
+ "mp4",
+ "m4a",
+ "avi",
+ "wmv",
+ "mpg",
+ NULL
+};
+
+/* Format descriptor */
+static sox_format_t sox_ffmpeg_format = {+ names,
+ SOX_FILE_NOSTDIO,
+ sox_ffmpeg_startread,
+ sox_ffmpeg_read,
+ sox_ffmpeg_stopread,
+ sox_ffmpeg_startwrite,
+ sox_format_nothing_write,
+ sox_format_nothing,
+ sox_format_nothing_seek
+};
+
+const sox_format_t *sox_ffmpeg_format_fn(void)
+{+ return &sox_ffmpeg_format;
+}
+
+#endif