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Diffstat (limited to 'doc/examples/output.c')
-rw-r--r-- | doc/examples/output.c | 663 |
1 files changed, 0 insertions, 663 deletions
diff --git a/doc/examples/output.c b/doc/examples/output.c deleted file mode 100644 index 0534554..0000000 --- a/doc/examples/output.c +++ /dev/null @@ -1,663 +0,0 @@ -/* - * 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. - */ - -/** - * @file - * libavformat API example. - * - * @example output.c - * Output a media file in any supported libavformat format. The default - * codecs are used. - */ - -#include <stdlib.h> -#include <stdio.h> -#include <string.h> -#include <math.h> - -#include "libavutil/channel_layout.h" -#include "libavutil/mathematics.h" -#include "libavutil/opt.h" -#include "libavformat/avformat.h" -#include "libavresample/avresample.h" -#include "libswscale/swscale.h" - -/* 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 AV_PIX_FMT_YUV420P /* default pix_fmt */ - -#define SCALE_FLAGS SWS_BICUBIC - -// a wrapper around a single output AVStream -typedef struct OutputStream { - AVStream *st; - - /* pts of the next frame that will be generated */ - int64_t next_pts; - - AVFrame *frame; - AVFrame *tmp_frame; - - float t, tincr, tincr2; - - struct SwsContext *sws_ctx; - AVAudioResampleContext *avr; -} OutputStream; - -/**************************************************************/ -/* audio output */ - -/* - * add an audio output stream - */ -static void add_audio_stream(OutputStream *ost, AVFormatContext *oc, - enum AVCodecID codec_id) -{ - AVCodecContext *c; - AVCodec *codec; - int ret; - - /* find the audio encoder */ - codec = avcodec_find_encoder(codec_id); - if (!codec) { - fprintf(stderr, "codec not found\n"); - exit(1); - } - - ost->st = avformat_new_stream(oc, codec); - if (!ost->st) { - fprintf(stderr, "Could not alloc stream\n"); - exit(1); - } - - c = ost->st->codec; - - /* put sample parameters */ - c->sample_fmt = codec->sample_fmts ? codec->sample_fmts[0] : AV_SAMPLE_FMT_S16; - c->sample_rate = codec->supported_samplerates ? codec->supported_samplerates[0] : 44100; - c->channel_layout = codec->channel_layouts ? codec->channel_layouts[0] : AV_CH_LAYOUT_STEREO; - c->channels = av_get_channel_layout_nb_channels(c->channel_layout); - c->bit_rate = 64000; - - ost->st->time_base = (AVRational){ 1, c->sample_rate }; - - // some formats want stream headers to be separate - if (oc->oformat->flags & AVFMT_GLOBALHEADER) - c->flags |= CODEC_FLAG_GLOBAL_HEADER; - - /* initialize sample format conversion; - * to simplify the code, we always pass the data through lavr, even - * if the encoder supports the generated format directly -- the price is - * some extra data copying; - */ - ost->avr = avresample_alloc_context(); - if (!ost->avr) { - fprintf(stderr, "Error allocating the resampling context\n"); - exit(1); - } - - av_opt_set_int(ost->avr, "in_sample_fmt", AV_SAMPLE_FMT_S16, 0); - av_opt_set_int(ost->avr, "in_sample_rate", 44100, 0); - av_opt_set_int(ost->avr, "in_channel_layout", AV_CH_LAYOUT_STEREO, 0); - av_opt_set_int(ost->avr, "out_sample_fmt", c->sample_fmt, 0); - av_opt_set_int(ost->avr, "out_sample_rate", c->sample_rate, 0); - av_opt_set_int(ost->avr, "out_channel_layout", c->channel_layout, 0); - - ret = avresample_open(ost->avr); - if (ret < 0) { - fprintf(stderr, "Error opening the resampling context\n"); - exit(1); - } -} - -static AVFrame *alloc_audio_frame(enum AVSampleFormat sample_fmt, - uint64_t channel_layout, - int sample_rate, int nb_samples) -{ - AVFrame *frame = av_frame_alloc(); - int ret; - - if (!frame) { - fprintf(stderr, "Error allocating an audio frame\n"); - exit(1); - } - - frame->format = sample_fmt; - frame->channel_layout = channel_layout; - frame->sample_rate = sample_rate; - frame->nb_samples = nb_samples; - - if (nb_samples) { - ret = av_frame_get_buffer(frame, 0); - if (ret < 0) { - fprintf(stderr, "Error allocating an audio buffer\n"); - exit(1); - } - } - - return frame; -} - -static void open_audio(AVFormatContext *oc, OutputStream *ost) -{ - AVCodecContext *c; - int nb_samples; - - c = ost->st->codec; - - /* open it */ - if (avcodec_open2(c, NULL, NULL) < 0) { - fprintf(stderr, "could not open codec\n"); - exit(1); - } - - /* init signal generator */ - ost->t = 0; - ost->tincr = 2 * M_PI * 110.0 / c->sample_rate; - /* increment frequency by 110 Hz per second */ - ost->tincr2 = 2 * M_PI * 110.0 / c->sample_rate / c->sample_rate; - - if (c->codec->capabilities & CODEC_CAP_VARIABLE_FRAME_SIZE) - nb_samples = 10000; - else - nb_samples = c->frame_size; - - ost->frame = alloc_audio_frame(c->sample_fmt, c->channel_layout, - c->sample_rate, nb_samples); - ost->tmp_frame = alloc_audio_frame(AV_SAMPLE_FMT_S16, AV_CH_LAYOUT_STEREO, - 44100, nb_samples); -} - -/* Prepare a 16 bit dummy audio frame of 'frame_size' samples and - * 'nb_channels' channels. */ -static AVFrame *get_audio_frame(OutputStream *ost) -{ - AVFrame *frame = ost->tmp_frame; - int j, i, v; - int16_t *q = (int16_t*)frame->data[0]; - - /* check if we want to generate more frames */ - if (av_compare_ts(ost->next_pts, ost->st->codec->time_base, - STREAM_DURATION, (AVRational){ 1, 1 }) >= 0) - return NULL; - - - for (j = 0; j < frame->nb_samples; j++) { - v = (int)(sin(ost->t) * 10000); - for (i = 0; i < ost->st->codec->channels; i++) - *q++ = v; - ost->t += ost->tincr; - ost->tincr += ost->tincr2; - } - - return frame; -} - -/* if a frame is provided, send it to the encoder, otherwise flush the encoder; - * return 1 when encoding is finished, 0 otherwise - */ -static int encode_audio_frame(AVFormatContext *oc, OutputStream *ost, - AVFrame *frame) -{ - AVPacket pkt = { 0 }; // data and size must be 0; - int got_packet; - - av_init_packet(&pkt); - avcodec_encode_audio2(ost->st->codec, &pkt, frame, &got_packet); - - if (got_packet) { - pkt.stream_index = ost->st->index; - - av_packet_rescale_ts(&pkt, ost->st->codec->time_base, ost->st->time_base); - - /* Write the compressed frame to the media file. */ - if (av_interleaved_write_frame(oc, &pkt) != 0) { - fprintf(stderr, "Error while writing audio frame\n"); - exit(1); - } - } - - return (frame || got_packet) ? 0 : 1; -} - -/* - * encode one audio frame and send it to the muxer - * return 1 when encoding is finished, 0 otherwise - */ -static int process_audio_stream(AVFormatContext *oc, OutputStream *ost) -{ - AVFrame *frame; - int got_output = 0; - int ret; - - frame = get_audio_frame(ost); - got_output |= !!frame; - - /* feed the data to lavr */ - if (frame) { - ret = avresample_convert(ost->avr, NULL, 0, 0, - frame->extended_data, frame->linesize[0], - frame->nb_samples); - if (ret < 0) { - fprintf(stderr, "Error feeding audio data to the resampler\n"); - exit(1); - } - } - - while ((frame && avresample_available(ost->avr) >= ost->frame->nb_samples) || - (!frame && avresample_get_out_samples(ost->avr, 0))) { - /* when we pass a frame to the encoder, it may keep a reference to it - * internally; - * make sure we do not overwrite it here - */ - ret = av_frame_make_writable(ost->frame); - if (ret < 0) - exit(1); - - /* the difference between the two avresample calls here is that the - * first one just reads the already converted data that is buffered in - * the lavr output buffer, while the second one also flushes the - * resampler */ - if (frame) { - ret = avresample_read(ost->avr, ost->frame->extended_data, - ost->frame->nb_samples); - } else { - ret = avresample_convert(ost->avr, ost->frame->extended_data, - ost->frame->linesize[0], ost->frame->nb_samples, - NULL, 0, 0); - } - - if (ret < 0) { - fprintf(stderr, "Error while resampling\n"); - exit(1); - } else if (frame && ret != ost->frame->nb_samples) { - fprintf(stderr, "Too few samples returned from lavr\n"); - exit(1); - } - - ost->frame->nb_samples = ret; - - ost->frame->pts = ost->next_pts; - ost->next_pts += ost->frame->nb_samples; - - got_output |= encode_audio_frame(oc, ost, ret ? ost->frame : NULL); - } - - return !got_output; -} - -/**************************************************************/ -/* video output */ - -/* Add a video output stream. */ -static void add_video_stream(OutputStream *ost, AVFormatContext *oc, - enum AVCodecID codec_id) -{ - AVCodecContext *c; - AVCodec *codec; - - /* find the video encoder */ - codec = avcodec_find_encoder(codec_id); - if (!codec) { - fprintf(stderr, "codec not found\n"); - exit(1); - } - - ost->st = avformat_new_stream(oc, codec); - if (!ost->st) { - fprintf(stderr, "Could not alloc stream\n"); - exit(1); - } - - c = ost->st->codec; - - /* Put sample parameters. */ - c->bit_rate = 400000; - /* Resolution must be a multiple of two. */ - c->width = 352; - c->height = 288; - /* timebase: 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 - * identical to 1. */ - ost->st->time_base = (AVRational){ 1, STREAM_FRAME_RATE }; - c->time_base = ost->st->time_base; - - c->gop_size = 12; /* emit one intra frame every twelve frames at most */ - c->pix_fmt = STREAM_PIX_FMT; - if (c->codec_id == AV_CODEC_ID_MPEG2VIDEO) { - /* just for testing, we also add B frames */ - c->max_b_frames = 2; - } - if (c->codec_id == AV_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; -} - -static AVFrame *alloc_picture(enum AVPixelFormat pix_fmt, int width, int height) -{ - AVFrame *picture; - int ret; - - picture = av_frame_alloc(); - if (!picture) - return NULL; - - picture->format = pix_fmt; - picture->width = width; - picture->height = height; - - /* allocate the buffers for the frame data */ - ret = av_frame_get_buffer(picture, 32); - if (ret < 0) { - fprintf(stderr, "Could not allocate frame data.\n"); - exit(1); - } - - return picture; -} - -static void open_video(AVFormatContext *oc, OutputStream *ost) -{ - AVCodecContext *c; - - c = ost->st->codec; - - /* open the codec */ - if (avcodec_open2(c, NULL, NULL) < 0) { - fprintf(stderr, "could not open codec\n"); - exit(1); - } - - /* Allocate the encoded raw picture. */ - ost->frame = alloc_picture(c->pix_fmt, c->width, c->height); - if (!ost->frame) { - 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. */ - ost->tmp_frame = NULL; - if (c->pix_fmt != AV_PIX_FMT_YUV420P) { - ost->tmp_frame = alloc_picture(AV_PIX_FMT_YUV420P, c->width, c->height); - if (!ost->tmp_frame) { - 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, ret; - - /* when we pass a frame to the encoder, it may keep a reference to it - * internally; - * make sure we do not overwrite it here - */ - ret = av_frame_make_writable(pict); - if (ret < 0) - exit(1); - - 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 AVFrame *get_video_frame(OutputStream *ost) -{ - AVCodecContext *c = ost->st->codec; - - /* check if we want to generate more frames */ - if (av_compare_ts(ost->next_pts, ost->st->codec->time_base, - STREAM_DURATION, (AVRational){ 1, 1 }) >= 0) - return NULL; - - if (c->pix_fmt != AV_PIX_FMT_YUV420P) { - /* as we only generate a YUV420P picture, we must convert it - * to the codec pixel format if needed */ - if (!ost->sws_ctx) { - ost->sws_ctx = sws_getContext(c->width, c->height, - AV_PIX_FMT_YUV420P, - c->width, c->height, - c->pix_fmt, - SCALE_FLAGS, NULL, NULL, NULL); - if (!ost->sws_ctx) { - fprintf(stderr, - "Cannot initialize the conversion context\n"); - exit(1); - } - } - fill_yuv_image(ost->tmp_frame, ost->next_pts, c->width, c->height); - sws_scale(ost->sws_ctx, ost->tmp_frame->data, ost->tmp_frame->linesize, - 0, c->height, ost->frame->data, ost->frame->linesize); - } else { - fill_yuv_image(ost->frame, ost->next_pts, c->width, c->height); - } - - ost->frame->pts = ost->next_pts++; - - return ost->frame; -} - -/* - * encode one video frame and send it to the muxer - * return 1 when encoding is finished, 0 otherwise - */ -static int write_video_frame(AVFormatContext *oc, OutputStream *ost) -{ - int ret; - AVCodecContext *c; - AVFrame *frame; - int got_packet = 0; - - c = ost->st->codec; - - frame = get_video_frame(ost); - - if (oc->oformat->flags & AVFMT_RAWPICTURE) { - /* a hack to avoid data copy with some raw video muxers */ - AVPacket pkt; - av_init_packet(&pkt); - - if (!frame) - return 1; - - pkt.flags |= AV_PKT_FLAG_KEY; - pkt.stream_index = ost->st->index; - pkt.data = (uint8_t *)frame; - pkt.size = sizeof(AVPicture); - - pkt.pts = pkt.dts = frame->pts; - av_packet_rescale_ts(&pkt, c->time_base, ost->st->time_base); - - ret = av_interleaved_write_frame(oc, &pkt); - } else { - AVPacket pkt = { 0 }; - av_init_packet(&pkt); - - /* encode the image */ - ret = avcodec_encode_video2(c, &pkt, frame, &got_packet); - if (ret < 0) { - fprintf(stderr, "Error encoding a video frame\n"); - exit(1); - } - - if (got_packet) { - av_packet_rescale_ts(&pkt, c->time_base, ost->st->time_base); - pkt.stream_index = ost->st->index; - - /* Write the compressed frame to the media file. */ - ret = av_interleaved_write_frame(oc, &pkt); - } - } - if (ret != 0) { - fprintf(stderr, "Error while writing video frame\n"); - exit(1); - } - - return (frame || got_packet) ? 0 : 1; -} - -static void close_stream(AVFormatContext *oc, OutputStream *ost) -{ - avcodec_close(ost->st->codec); - av_frame_free(&ost->frame); - av_frame_free(&ost->tmp_frame); - sws_freeContext(ost->sws_ctx); - avresample_free(&ost->avr); -} - -/**************************************************************/ -/* media file output */ - -int main(int argc, char **argv) -{ - OutputStream video_st = { 0 }, audio_st = { 0 }; - const char *filename; - AVOutputFormat *fmt; - AVFormatContext *oc; - int have_video = 0, have_audio = 0; - int encode_video = 0, encode_audio = 0; - - /* 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]); - return 1; - } - - filename = argv[1]; - - /* Autodetect the output format from the name. default is MPEG. */ - fmt = av_guess_format(NULL, filename, NULL); - if (!fmt) { - printf("Could not deduce output format from file extension: using MPEG.\n"); - fmt = av_guess_format("mpeg", NULL, NULL); - } - if (!fmt) { - fprintf(stderr, "Could not find suitable output format\n"); - return 1; - } - - /* Allocate the output media context. */ - oc = avformat_alloc_context(); - if (!oc) { - fprintf(stderr, "Memory error\n"); - return 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. */ - if (fmt->video_codec != AV_CODEC_ID_NONE) { - add_video_stream(&video_st, oc, fmt->video_codec); - have_video = 1; - encode_video = 1; - } - if (fmt->audio_codec != AV_CODEC_ID_NONE) { - add_audio_stream(&audio_st, oc, fmt->audio_codec); - have_audio = 1; - encode_audio = 1; - } - - /* Now that all the parameters are set, we can open the audio and - * video codecs and allocate the necessary encode buffers. */ - if (have_video) - open_video(oc, &video_st); - if (have_audio) - open_audio(oc, &audio_st); - - av_dump_format(oc, 0, filename, 1); - - /* open the output file, if needed */ - if (!(fmt->flags & AVFMT_NOFILE)) { - if (avio_open(&oc->pb, filename, AVIO_FLAG_WRITE) < 0) { - fprintf(stderr, "Could not open '%s'\n", filename); - return 1; - } - } - - /* Write the stream header, if any. */ - avformat_write_header(oc, NULL); - - while (encode_video || encode_audio) { - /* select the stream to encode */ - if (encode_video && - (!encode_audio || av_compare_ts(video_st.next_pts, video_st.st->codec->time_base, - audio_st.next_pts, audio_st.st->codec->time_base) <= 0)) { - encode_video = !write_video_frame(oc, &video_st); - } else { - encode_audio = !process_audio_stream(oc, &audio_st); - } - } - - /* Write the trailer, if any. The trailer must be written before you - * close the CodecContexts open when you wrote the header; otherwise - * av_write_trailer() may try to use memory that was freed on - * av_codec_close(). */ - av_write_trailer(oc); - - /* Close each codec. */ - if (have_video) - close_stream(oc, &video_st); - if (have_audio) - close_stream(oc, &audio_st); - - if (!(fmt->flags & AVFMT_NOFILE)) - /* Close the output file. */ - avio_close(oc->pb); - - /* free the stream */ - avformat_free_context(oc); - - return 0; -} |