Move output_example.c --> libavformat/output-example.c.

The libavformat directory is a better place for a libavformat API example.

Originally committed as revision 18199 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 553 insertions, 0 deletions

diff --git a/libavformat/output-example.c b/libavformat/output-example.c
new file mode 100644
index 0000000000..c6cd99f7b8
--- /dev/null
+++ b/libavformat/output-example.c
@@ -0,0 +1,553 @@
+/*
+ * Libavformat API example: Output a media file in any supported
+ * libavformat format. The default codecs are used.
+ *
+ * Copyright (c) 2003 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <math.h>
+
+#ifndef M_PI
+#define M_PI 3.14159265358979323846
+#endif
+
+#include "libavformat/avformat.h"
+#include "libswscale/swscale.h"
+
+#undef exit
+
+/* 5 seconds stream duration */
+#define STREAM_DURATION   5.0
+#define STREAM_FRAME_RATE 25 /* 25 images/s */
+#define STREAM_NB_FRAMES  ((int)(STREAM_DURATION * STREAM_FRAME_RATE))
+#define STREAM_PIX_FMT PIX_FMT_YUV420P /* default pix_fmt */
+
+static int sws_flags = SWS_BICUBIC;
+
+/**************************************************************/
+/* audio output */
+
+float t, tincr, tincr2;
+int16_t *samples;
+uint8_t *audio_outbuf;
+int audio_outbuf_size;
+int audio_input_frame_size;
+
+/*
+ * add an audio output stream
+ */
+static AVStream *add_audio_stream(AVFormatContext *oc, int codec_id)
+{
+    AVCodecContext *c;
+    AVStream *st;
+
+    st = av_new_stream(oc, 1);
+    if (!st) {
+        fprintf(stderr, "Could not alloc stream\n");
+        exit(1);
+    }
+
+    c = st->codec;
+    c->codec_id = codec_id;
+    c->codec_type = CODEC_TYPE_AUDIO;
+
+    /* put sample parameters */
+    c->bit_rate = 64000;
+    c->sample_rate = 44100;
+    c->channels = 2;
+    return st;
+}
+
+static void open_audio(AVFormatContext *oc, AVStream *st)
+{
+    AVCodecContext *c;
+    AVCodec *codec;
+
+    c = st->codec;
+
+    /* find the audio encoder */
+    codec = avcodec_find_encoder(c->codec_id);
+    if (!codec) {
+        fprintf(stderr, "codec not found\n");
+        exit(1);
+    }
+
+    /* open it */
+    if (avcodec_open(c, codec) < 0) {
+        fprintf(stderr, "could not open codec\n");
+        exit(1);
+    }
+
+    /* init signal generator */
+    t = 0;
+    tincr = 2 * M_PI * 110.0 / c->sample_rate;
+    /* increment frequency by 110 Hz per second */
+    tincr2 = 2 * M_PI * 110.0 / c->sample_rate / c->sample_rate;
+
+    audio_outbuf_size = 10000;
+    audio_outbuf = av_malloc(audio_outbuf_size);
+
+    /* ugly hack for PCM codecs (will be removed ASAP with new PCM
+       support to compute the input frame size in samples */
+    if (c->frame_size <= 1) {
+        audio_input_frame_size = audio_outbuf_size / c->channels;
+        switch(st->codec->codec_id) {
+        case CODEC_ID_PCM_S16LE:
+        case CODEC_ID_PCM_S16BE:
+        case CODEC_ID_PCM_U16LE:
+        case CODEC_ID_PCM_U16BE:
+            audio_input_frame_size >>= 1;
+            break;
+        default:
+            break;
+        }
+    } else {
+        audio_input_frame_size = c->frame_size;
+    }
+    samples = av_malloc(audio_input_frame_size * 2 * c->channels);
+}
+
+/* prepare a 16 bit dummy audio frame of 'frame_size' samples and
+   'nb_channels' channels */
+static void get_audio_frame(int16_t *samples, int frame_size, int nb_channels)
+{
+    int j, i, v;
+    int16_t *q;
+
+    q = samples;
+    for(j=0;j<frame_size;j++) {
+        v = (int)(sin(t) * 10000);
+        for(i = 0; i < nb_channels; i++)
+            *q++ = v;
+        t += tincr;
+        tincr += tincr2;
+    }
+}
+
+static void write_audio_frame(AVFormatContext *oc, AVStream *st)
+{
+    AVCodecContext *c;
+    AVPacket pkt;
+    av_init_packet(&pkt);
+
+    c = st->codec;
+
+    get_audio_frame(samples, audio_input_frame_size, c->channels);
+
+    pkt.size= avcodec_encode_audio(c, audio_outbuf, audio_outbuf_size, samples);
+
+    if (c->coded_frame->pts != AV_NOPTS_VALUE)
+        pkt.pts= av_rescale_q(c->coded_frame->pts, c->time_base, st->time_base);
+    pkt.flags |= PKT_FLAG_KEY;
+    pkt.stream_index= st->index;
+    pkt.data= audio_outbuf;
+
+    /* write the compressed frame in the media file */
+    if (av_interleaved_write_frame(oc, &pkt) != 0) {
+        fprintf(stderr, "Error while writing audio frame\n");
+        exit(1);
+    }
+}
+
+static void close_audio(AVFormatContext *oc, AVStream *st)
+{
+    avcodec_close(st->codec);
+
+    av_free(samples);
+    av_free(audio_outbuf);
+}
+
+/**************************************************************/
+/* video output */
+
+AVFrame *picture, *tmp_picture;
+uint8_t *video_outbuf;
+int frame_count, video_outbuf_size;
+
+/* add a video output stream */
+static AVStream *add_video_stream(AVFormatContext *oc, int codec_id)
+{
+    AVCodecContext *c;
+    AVStream *st;
+
+    st = av_new_stream(oc, 0);
+    if (!st) {
+        fprintf(stderr, "Could not alloc stream\n");
+        exit(1);
+    }
+
+    c = st->codec;
+    c->codec_id = codec_id;
+    c->codec_type = CODEC_TYPE_VIDEO;
+
+    /* put sample parameters */
+    c->bit_rate = 400000;
+    /* resolution must be a multiple of two */
+    c->width = 352;
+    c->height = 288;
+    /* time base: this is the fundamental unit of time (in seconds) in terms
+       of which frame timestamps are represented. for fixed-fps content,
+       timebase should be 1/framerate and timestamp increments should be
+       identically 1. */
+    c->time_base.den = STREAM_FRAME_RATE;
+    c->time_base.num = 1;
+    c->gop_size = 12; /* emit one intra frame every twelve frames at most */
+    c->pix_fmt = STREAM_PIX_FMT;
+    if (c->codec_id == CODEC_ID_MPEG2VIDEO) {
+        /* just for testing, we also add B frames */
+        c->max_b_frames = 2;
+    }
+    if (c->codec_id == CODEC_ID_MPEG1VIDEO){
+        /* Needed to avoid using macroblocks in which some coeffs overflow.
+           This does not happen with normal video, it just happens here as
+           the motion of the chroma plane does not match the luma plane. */
+        c->mb_decision=2;
+    }
+    // some formats want stream headers to be separate
+    if(oc->oformat->flags & AVFMT_GLOBALHEADER)
+        c->flags |= CODEC_FLAG_GLOBAL_HEADER;
+
+    return st;
+}
+
+static AVFrame *alloc_picture(int pix_fmt, int width, int height)
+{
+    AVFrame *picture;
+    uint8_t *picture_buf;
+    int size;
+
+    picture = avcodec_alloc_frame();
+    if (!picture)
+        return NULL;
+    size = avpicture_get_size(pix_fmt, width, height);
+    picture_buf = av_malloc(size);
+    if (!picture_buf) {
+        av_free(picture);
+        return NULL;
+    }
+    avpicture_fill((AVPicture *)picture, picture_buf,
+                   pix_fmt, width, height);
+    return picture;
+}
+
+static void open_video(AVFormatContext *oc, AVStream *st)
+{
+    AVCodec *codec;
+    AVCodecContext *c;
+
+    c = st->codec;
+
+    /* find the video encoder */
+    codec = avcodec_find_encoder(c->codec_id);
+    if (!codec) {
+        fprintf(stderr, "codec not found\n");
+        exit(1);
+    }
+
+    /* open the codec */
+    if (avcodec_open(c, codec) < 0) {
+        fprintf(stderr, "could not open codec\n");
+        exit(1);
+    }
+
+    video_outbuf = NULL;
+    if (!(oc->oformat->flags & AVFMT_RAWPICTURE)) {
+        /* allocate output buffer */
+        /* XXX: API change will be done */
+        /* buffers passed into lav* can be allocated any way you prefer,
+           as long as they're aligned enough for the architecture, and
+           they're freed appropriately (such as using av_free for buffers
+           allocated with av_malloc) */
+        video_outbuf_size = 200000;
+        video_outbuf = av_malloc(video_outbuf_size);
+    }
+
+    /* allocate the encoded raw picture */
+    picture = alloc_picture(c->pix_fmt, c->width, c->height);
+    if (!picture) {
+        fprintf(stderr, "Could not allocate picture\n");
+        exit(1);
+    }
+
+    /* if the output format is not YUV420P, then a temporary YUV420P
+       picture is needed too. It is then converted to the required
+       output format */
+    tmp_picture = NULL;
+    if (c->pix_fmt != PIX_FMT_YUV420P) {
+        tmp_picture = alloc_picture(PIX_FMT_YUV420P, c->width, c->height);
+        if (!tmp_picture) {
+            fprintf(stderr, "Could not allocate temporary picture\n");
+            exit(1);
+        }
+    }
+}
+
+/* prepare a dummy image */
+static void fill_yuv_image(AVFrame *pict, int frame_index, int width, int height)
+{
+    int x, y, i;
+
+    i = frame_index;
+
+    /* Y */
+    for(y=0;y<height;y++) {
+        for(x=0;x<width;x++) {
+            pict->data[0][y * pict->linesize[0] + x] = x + y + i * 3;
+        }
+    }
+
+    /* Cb and Cr */
+    for(y=0;y<height/2;y++) {
+        for(x=0;x<width/2;x++) {
+            pict->data[1][y * pict->linesize[1] + x] = 128 + y + i * 2;
+            pict->data[2][y * pict->linesize[2] + x] = 64 + x + i * 5;
+        }
+    }
+}
+
+static void write_video_frame(AVFormatContext *oc, AVStream *st)
+{
+    int out_size, ret;
+    AVCodecContext *c;
+    static struct SwsContext *img_convert_ctx;
+
+    c = st->codec;
+
+    if (frame_count >= STREAM_NB_FRAMES) {
+        /* no more frame to compress. The codec has a latency of a few
+           frames if using B frames, so we get the last frames by
+           passing the same picture again */
+    } else {
+        if (c->pix_fmt != PIX_FMT_YUV420P) {
+            /* as we only generate a YUV420P picture, we must convert it
+               to the codec pixel format if needed */
+            if (img_convert_ctx == NULL) {
+                img_convert_ctx = sws_getContext(c->width, c->height,
+                                                 PIX_FMT_YUV420P,
+                                                 c->width, c->height,
+                                                 c->pix_fmt,
+                                                 sws_flags, NULL, NULL, NULL);
+                if (img_convert_ctx == NULL) {
+                    fprintf(stderr, "Cannot initialize the conversion context\n");
+                    exit(1);
+                }
+            }
+            fill_yuv_image(tmp_picture, frame_count, c->width, c->height);
+            sws_scale(img_convert_ctx, tmp_picture->data, tmp_picture->linesize,
+                      0, c->height, picture->data, picture->linesize);
+        } else {
+            fill_yuv_image(picture, frame_count, c->width, c->height);
+        }
+    }
+
+
+    if (oc->oformat->flags & AVFMT_RAWPICTURE) {
+        /* raw video case. The API will change slightly in the near
+           futur for that */
+        AVPacket pkt;
+        av_init_packet(&pkt);
+
+        pkt.flags |= PKT_FLAG_KEY;
+        pkt.stream_index= st->index;
+        pkt.data= (uint8_t *)picture;
+        pkt.size= sizeof(AVPicture);
+
+        ret = av_interleaved_write_frame(oc, &pkt);
+    } else {
+        /* encode the image */
+        out_size = avcodec_encode_video(c, video_outbuf, video_outbuf_size, picture);
+        /* if zero size, it means the image was buffered */
+        if (out_size > 0) {
+            AVPacket pkt;
+            av_init_packet(&pkt);
+
+            if (c->coded_frame->pts != AV_NOPTS_VALUE)
+                pkt.pts= av_rescale_q(c->coded_frame->pts, c->time_base, st->time_base);
+            if(c->coded_frame->key_frame)
+                pkt.flags |= PKT_FLAG_KEY;
+            pkt.stream_index= st->index;
+            pkt.data= video_outbuf;
+            pkt.size= out_size;
+
+            /* write the compressed frame in the media file */
+            ret = av_interleaved_write_frame(oc, &pkt);
+        } else {
+            ret = 0;
+        }
+    }
+    if (ret != 0) {
+        fprintf(stderr, "Error while writing video frame\n");
+        exit(1);
+    }
+    frame_count++;
+}
+
+static void close_video(AVFormatContext *oc, AVStream *st)
+{
+    avcodec_close(st->codec);
+    av_free(picture->data[0]);
+    av_free(picture);
+    if (tmp_picture) {
+        av_free(tmp_picture->data[0]);
+        av_free(tmp_picture);
+    }
+    av_free(video_outbuf);
+}
+
+/**************************************************************/
+/* media file output */
+
+int main(int argc, char **argv)
+{
+    const char *filename;
+    AVOutputFormat *fmt;
+    AVFormatContext *oc;
+    AVStream *audio_st, *video_st;
+    double audio_pts, video_pts;
+    int i;
+
+    /* initialize libavcodec, and register all codecs and formats */
+    av_register_all();
+
+    if (argc != 2) {
+        printf("usage: %s output_file\n"
+               "API example program to output a media file with libavformat.\n"
+               "The output format is automatically guessed according to the file extension.\n"
+               "Raw images can also be output by using '%%d' in the filename\n"
+               "\n", argv[0]);
+        exit(1);
+    }
+
+    filename = argv[1];
+
+    /* auto detect the output format from the name. default is
+       mpeg. */
+    fmt = guess_format(NULL, filename, NULL);
+    if (!fmt) {
+        printf("Could not deduce output format from file extension: using MPEG.\n");
+        fmt = guess_format("mpeg", NULL, NULL);
+    }
+    if (!fmt) {
+        fprintf(stderr, "Could not find suitable output format\n");
+        exit(1);
+    }
+
+    /* allocate the output media context */
+    oc = avformat_alloc_context();
+    if (!oc) {
+        fprintf(stderr, "Memory error\n");
+        exit(1);
+    }
+    oc->oformat = fmt;
+    snprintf(oc->filename, sizeof(oc->filename), "%s", filename);
+
+    /* add the audio and video streams using the default format codecs
+       and initialize the codecs */
+    video_st = NULL;
+    audio_st = NULL;
+    if (fmt->video_codec != CODEC_ID_NONE) {
+        video_st = add_video_stream(oc, fmt->video_codec);
+    }
+    if (fmt->audio_codec != CODEC_ID_NONE) {
+        audio_st = add_audio_stream(oc, fmt->audio_codec);
+    }
+
+    /* set the output parameters (must be done even if no
+       parameters). */
+    if (av_set_parameters(oc, NULL) < 0) {
+        fprintf(stderr, "Invalid output format parameters\n");
+        exit(1);
+    }
+
+    dump_format(oc, 0, filename, 1);
+
+    /* now that all the parameters are set, we can open the audio and
+       video codecs and allocate the necessary encode buffers */
+    if (video_st)
+        open_video(oc, video_st);
+    if (audio_st)
+        open_audio(oc, audio_st);
+
+    /* open the output file, if needed */
+    if (!(fmt->flags & AVFMT_NOFILE)) {
+        if (url_fopen(&oc->pb, filename, URL_WRONLY) < 0) {
+            fprintf(stderr, "Could not open '%s'\n", filename);
+            exit(1);
+        }
+    }
+
+    /* write the stream header, if any */
+    av_write_header(oc);
+
+    for(;;) {
+        /* compute current audio and video time */
+        if (audio_st)
+            audio_pts = (double)audio_st->pts.val * audio_st->time_base.num / audio_st->time_base.den;
+        else
+            audio_pts = 0.0;
+
+        if (video_st)
+            video_pts = (double)video_st->pts.val * video_st->time_base.num / video_st->time_base.den;
+        else
+            video_pts = 0.0;
+
+        if ((!audio_st || audio_pts >= STREAM_DURATION) &&
+            (!video_st || video_pts >= STREAM_DURATION))
+            break;
+
+        /* write interleaved audio and video frames */
+        if (!video_st || (video_st && audio_st && audio_pts < video_pts)) {
+            write_audio_frame(oc, audio_st);
+        } else {
+            write_video_frame(oc, video_st);
+        }
+    }
+
+    /* write the trailer, if any.  the trailer must be written
+     * before you close the CodecContexts open when you wrote the
+     * header; otherwise write_trailer may try to use memory that
+     * was freed on av_codec_close() */
+    av_write_trailer(oc);
+
+    /* close each codec */
+    if (video_st)
+        close_video(oc, video_st);
+    if (audio_st)
+        close_audio(oc, audio_st);
+
+    /* free the streams */
+    for(i = 0; i < oc->nb_streams; i++) {
+        av_freep(&oc->streams[i]->codec);
+        av_freep(&oc->streams[i]);
+    }
+
+    if (!(fmt->flags & AVFMT_NOFILE)) {
+        /* close the output file */
+        url_fclose(oc->pb);
+    }
+
+    /* free the stream */
+    av_free(oc);
+
+    return 0;
+}