diff options
author | Stefano Sabatini <stefasab@gmail.com> | 2014-04-01 13:12:51 +0400 |
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committer | Stefano Sabatini <stefasab@gmail.com> | 2014-04-23 12:32:42 +0400 |
commit | bf411fffd4535458bf3ad68ca3b9947458961abe (patch) | |
tree | 416e81319dc5f292ba09843445c3666587e31325 /doc/examples/avcodec.c | |
parent | dc6a17cf74a90e41d70ea1753cdb70c0a5b2ced8 (diff) |
examples: rename avcodec.c to decoding_encoding.c
Restore the old name, which was more meaningful and consistent with the
names of the other examples.
Diffstat (limited to 'doc/examples/avcodec.c')
-rw-r--r-- | doc/examples/avcodec.c | 664 |
1 files changed, 0 insertions, 664 deletions
diff --git a/doc/examples/avcodec.c b/doc/examples/avcodec.c deleted file mode 100644 index 86727a7b48..0000000000 --- a/doc/examples/avcodec.c +++ /dev/null @@ -1,664 +0,0 @@ -/* - * Copyright (c) 2001 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 - * libavcodec API use example. - * - * @example avcodec.c - * Note that libavcodec only handles codecs (mpeg, mpeg4, etc...), - * not file formats (avi, vob, mp4, mov, mkv, mxf, flv, mpegts, mpegps, etc...). See library 'libavformat' for the - * format handling - */ - -#include <math.h> - -#include <libavutil/opt.h> -#include <libavcodec/avcodec.h> -#include <libavutil/channel_layout.h> -#include <libavutil/common.h> -#include <libavutil/imgutils.h> -#include <libavutil/mathematics.h> -#include <libavutil/samplefmt.h> - -#define INBUF_SIZE 4096 -#define AUDIO_INBUF_SIZE 20480 -#define AUDIO_REFILL_THRESH 4096 - -/* check that a given sample format is supported by the encoder */ -static int check_sample_fmt(AVCodec *codec, enum AVSampleFormat sample_fmt) -{ - const enum AVSampleFormat *p = codec->sample_fmts; - - while (*p != AV_SAMPLE_FMT_NONE) { - if (*p == sample_fmt) - return 1; - p++; - } - return 0; -} - -/* just pick the highest supported samplerate */ -static int select_sample_rate(AVCodec *codec) -{ - const int *p; - int best_samplerate = 0; - - if (!codec->supported_samplerates) - return 44100; - - p = codec->supported_samplerates; - while (*p) { - best_samplerate = FFMAX(*p, best_samplerate); - p++; - } - return best_samplerate; -} - -/* select layout with the highest channel count */ -static int select_channel_layout(AVCodec *codec) -{ - const uint64_t *p; - uint64_t best_ch_layout = 0; - int best_nb_channels = 0; - - if (!codec->channel_layouts) - return AV_CH_LAYOUT_STEREO; - - p = codec->channel_layouts; - while (*p) { - int nb_channels = av_get_channel_layout_nb_channels(*p); - - if (nb_channels > best_nb_channels) { - best_ch_layout = *p; - best_nb_channels = nb_channels; - } - p++; - } - return best_ch_layout; -} - -/* - * Audio encoding example - */ -static void audio_encode_example(const char *filename) -{ - AVCodec *codec; - AVCodecContext *c= NULL; - AVFrame *frame; - AVPacket pkt; - int i, j, k, ret, got_output; - int buffer_size; - FILE *f; - uint16_t *samples; - float t, tincr; - - printf("Encode audio file %s\n", filename); - - /* find the MP2 encoder */ - codec = avcodec_find_encoder(AV_CODEC_ID_MP2); - if (!codec) { - fprintf(stderr, "Codec not found\n"); - exit(1); - } - - c = avcodec_alloc_context3(codec); - if (!c) { - fprintf(stderr, "Could not allocate audio codec context\n"); - exit(1); - } - - /* put sample parameters */ - c->bit_rate = 64000; - - /* check that the encoder supports s16 pcm input */ - c->sample_fmt = AV_SAMPLE_FMT_S16; - if (!check_sample_fmt(codec, c->sample_fmt)) { - fprintf(stderr, "Encoder does not support sample format %s", - av_get_sample_fmt_name(c->sample_fmt)); - exit(1); - } - - /* select other audio parameters supported by the encoder */ - c->sample_rate = select_sample_rate(codec); - c->channel_layout = select_channel_layout(codec); - c->channels = av_get_channel_layout_nb_channels(c->channel_layout); - - /* open it */ - if (avcodec_open2(c, codec, NULL) < 0) { - fprintf(stderr, "Could not open codec\n"); - exit(1); - } - - f = fopen(filename, "wb"); - if (!f) { - fprintf(stderr, "Could not open %s\n", filename); - exit(1); - } - - /* frame containing input raw audio */ - frame = av_frame_alloc(); - if (!frame) { - fprintf(stderr, "Could not allocate audio frame\n"); - exit(1); - } - - frame->nb_samples = c->frame_size; - frame->format = c->sample_fmt; - frame->channel_layout = c->channel_layout; - - /* the codec gives us the frame size, in samples, - * we calculate the size of the samples buffer in bytes */ - buffer_size = av_samples_get_buffer_size(NULL, c->channels, c->frame_size, - c->sample_fmt, 0); - if (buffer_size < 0) { - fprintf(stderr, "Could not get sample buffer size\n"); - exit(1); - } - samples = av_malloc(buffer_size); - if (!samples) { - fprintf(stderr, "Could not allocate %d bytes for samples buffer\n", - buffer_size); - exit(1); - } - /* setup the data pointers in the AVFrame */ - ret = avcodec_fill_audio_frame(frame, c->channels, c->sample_fmt, - (const uint8_t*)samples, buffer_size, 0); - if (ret < 0) { - fprintf(stderr, "Could not setup audio frame\n"); - exit(1); - } - - /* encode a single tone sound */ - t = 0; - tincr = 2 * M_PI * 440.0 / c->sample_rate; - for (i = 0; i < 200; i++) { - av_init_packet(&pkt); - pkt.data = NULL; // packet data will be allocated by the encoder - pkt.size = 0; - - for (j = 0; j < c->frame_size; j++) { - samples[2*j] = (int)(sin(t) * 10000); - - for (k = 1; k < c->channels; k++) - samples[2*j + k] = samples[2*j]; - t += tincr; - } - /* encode the samples */ - ret = avcodec_encode_audio2(c, &pkt, frame, &got_output); - if (ret < 0) { - fprintf(stderr, "Error encoding audio frame\n"); - exit(1); - } - if (got_output) { - fwrite(pkt.data, 1, pkt.size, f); - av_free_packet(&pkt); - } - } - - /* get the delayed frames */ - for (got_output = 1; got_output; i++) { - ret = avcodec_encode_audio2(c, &pkt, NULL, &got_output); - if (ret < 0) { - fprintf(stderr, "Error encoding frame\n"); - exit(1); - } - - if (got_output) { - fwrite(pkt.data, 1, pkt.size, f); - av_free_packet(&pkt); - } - } - fclose(f); - - av_freep(&samples); - av_frame_free(&frame); - avcodec_close(c); - av_free(c); -} - -/* - * Audio decoding. - */ -static void audio_decode_example(const char *outfilename, const char *filename) -{ - AVCodec *codec; - AVCodecContext *c= NULL; - int len; - FILE *f, *outfile; - uint8_t inbuf[AUDIO_INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE]; - AVPacket avpkt; - AVFrame *decoded_frame = NULL; - - av_init_packet(&avpkt); - - printf("Decode audio file %s to %s\n", filename, outfilename); - - /* find the mpeg audio decoder */ - codec = avcodec_find_decoder(AV_CODEC_ID_MP2); - if (!codec) { - fprintf(stderr, "Codec not found\n"); - exit(1); - } - - c = avcodec_alloc_context3(codec); - if (!c) { - fprintf(stderr, "Could not allocate audio codec context\n"); - exit(1); - } - - /* open it */ - if (avcodec_open2(c, codec, NULL) < 0) { - fprintf(stderr, "Could not open codec\n"); - exit(1); - } - - f = fopen(filename, "rb"); - if (!f) { - fprintf(stderr, "Could not open %s\n", filename); - exit(1); - } - outfile = fopen(outfilename, "wb"); - if (!outfile) { - av_free(c); - exit(1); - } - - /* decode until eof */ - avpkt.data = inbuf; - avpkt.size = fread(inbuf, 1, AUDIO_INBUF_SIZE, f); - - while (avpkt.size > 0) { - int got_frame = 0; - - if (!decoded_frame) { - if (!(decoded_frame = av_frame_alloc())) { - fprintf(stderr, "Could not allocate audio frame\n"); - exit(1); - } - } - - len = avcodec_decode_audio4(c, decoded_frame, &got_frame, &avpkt); - if (len < 0) { - fprintf(stderr, "Error while decoding\n"); - exit(1); - } - if (got_frame) { - /* if a frame has been decoded, output it */ - int data_size = av_samples_get_buffer_size(NULL, c->channels, - decoded_frame->nb_samples, - c->sample_fmt, 1); - if (data_size < 0) { - /* This should not occur, checking just for paranoia */ - fprintf(stderr, "Failed to calculate data size\n"); - exit(1); - } - fwrite(decoded_frame->data[0], 1, data_size, outfile); - } - avpkt.size -= len; - avpkt.data += len; - avpkt.dts = - avpkt.pts = AV_NOPTS_VALUE; - if (avpkt.size < AUDIO_REFILL_THRESH) { - /* Refill the input buffer, to avoid trying to decode - * incomplete frames. Instead of this, one could also use - * a parser, or use a proper container format through - * libavformat. */ - memmove(inbuf, avpkt.data, avpkt.size); - avpkt.data = inbuf; - len = fread(avpkt.data + avpkt.size, 1, - AUDIO_INBUF_SIZE - avpkt.size, f); - if (len > 0) - avpkt.size += len; - } - } - - fclose(outfile); - fclose(f); - - avcodec_close(c); - av_free(c); - av_frame_free(&decoded_frame); -} - -/* - * Video encoding example - */ -static void video_encode_example(const char *filename, int codec_id) -{ - AVCodec *codec; - AVCodecContext *c= NULL; - int i, ret, x, y, got_output; - FILE *f; - AVFrame *frame; - AVPacket pkt; - uint8_t endcode[] = { 0, 0, 1, 0xb7 }; - - printf("Encode video file %s\n", filename); - - /* find the mpeg1 video encoder */ - codec = avcodec_find_encoder(codec_id); - if (!codec) { - fprintf(stderr, "Codec not found\n"); - exit(1); - } - - c = avcodec_alloc_context3(codec); - if (!c) { - fprintf(stderr, "Could not allocate video codec context\n"); - exit(1); - } - - /* put sample parameters */ - c->bit_rate = 400000; - /* resolution must be a multiple of two */ - c->width = 352; - c->height = 288; - /* frames per second */ - c->time_base = (AVRational){1,25}; - /* emit one intra frame every ten frames - * check frame pict_type before passing frame - * to encoder, if frame->pict_type is AV_PICTURE_TYPE_I - * then gop_size is ignored and the output of encoder - * will always be I frame irrespective to gop_size - */ - c->gop_size = 10; - c->max_b_frames = 1; - c->pix_fmt = AV_PIX_FMT_YUV420P; - - if (codec_id == AV_CODEC_ID_H264) - av_opt_set(c->priv_data, "preset", "slow", 0); - - /* open it */ - if (avcodec_open2(c, codec, NULL) < 0) { - fprintf(stderr, "Could not open codec\n"); - exit(1); - } - - f = fopen(filename, "wb"); - if (!f) { - fprintf(stderr, "Could not open %s\n", filename); - exit(1); - } - - frame = av_frame_alloc(); - if (!frame) { - fprintf(stderr, "Could not allocate video frame\n"); - exit(1); - } - frame->format = c->pix_fmt; - frame->width = c->width; - frame->height = c->height; - - /* the image can be allocated by any means and av_image_alloc() is - * just the most convenient way if av_malloc() is to be used */ - ret = av_image_alloc(frame->data, frame->linesize, c->width, c->height, - c->pix_fmt, 32); - if (ret < 0) { - fprintf(stderr, "Could not allocate raw picture buffer\n"); - exit(1); - } - - /* encode 1 second of video */ - for (i = 0; i < 25; i++) { - av_init_packet(&pkt); - pkt.data = NULL; // packet data will be allocated by the encoder - pkt.size = 0; - - fflush(stdout); - /* prepare a dummy image */ - /* Y */ - for (y = 0; y < c->height; y++) { - for (x = 0; x < c->width; x++) { - frame->data[0][y * frame->linesize[0] + x] = x + y + i * 3; - } - } - - /* Cb and Cr */ - for (y = 0; y < c->height/2; y++) { - for (x = 0; x < c->width/2; x++) { - frame->data[1][y * frame->linesize[1] + x] = 128 + y + i * 2; - frame->data[2][y * frame->linesize[2] + x] = 64 + x + i * 5; - } - } - - frame->pts = i; - - /* encode the image */ - ret = avcodec_encode_video2(c, &pkt, frame, &got_output); - if (ret < 0) { - fprintf(stderr, "Error encoding frame\n"); - exit(1); - } - - if (got_output) { - printf("Write frame %3d (size=%5d)\n", i, pkt.size); - fwrite(pkt.data, 1, pkt.size, f); - av_free_packet(&pkt); - } - } - - /* get the delayed frames */ - for (got_output = 1; got_output; i++) { - fflush(stdout); - - ret = avcodec_encode_video2(c, &pkt, NULL, &got_output); - if (ret < 0) { - fprintf(stderr, "Error encoding frame\n"); - exit(1); - } - - if (got_output) { - printf("Write frame %3d (size=%5d)\n", i, pkt.size); - fwrite(pkt.data, 1, pkt.size, f); - av_free_packet(&pkt); - } - } - - /* add sequence end code to have a real mpeg file */ - fwrite(endcode, 1, sizeof(endcode), f); - fclose(f); - - avcodec_close(c); - av_free(c); - av_freep(&frame->data[0]); - av_frame_free(&frame); - printf("\n"); -} - -/* - * Video decoding example - */ - -static void pgm_save(unsigned char *buf, int wrap, int xsize, int ysize, - char *filename) -{ - FILE *f; - int i; - - f = fopen(filename,"w"); - fprintf(f, "P5\n%d %d\n%d\n", xsize, ysize, 255); - for (i = 0; i < ysize; i++) - fwrite(buf + i * wrap, 1, xsize, f); - fclose(f); -} - -static int decode_write_frame(const char *outfilename, AVCodecContext *avctx, - AVFrame *frame, int *frame_count, AVPacket *pkt, int last) -{ - int len, got_frame; - char buf[1024]; - - len = avcodec_decode_video2(avctx, frame, &got_frame, pkt); - if (len < 0) { - fprintf(stderr, "Error while decoding frame %d\n", *frame_count); - return len; - } - if (got_frame) { - printf("Saving %sframe %3d\n", last ? "last " : "", *frame_count); - fflush(stdout); - - /* the picture is allocated by the decoder, no need to free it */ - snprintf(buf, sizeof(buf), outfilename, *frame_count); - pgm_save(frame->data[0], frame->linesize[0], - avctx->width, avctx->height, buf); - (*frame_count)++; - } - if (pkt->data) { - pkt->size -= len; - pkt->data += len; - } - return 0; -} - -static void video_decode_example(const char *outfilename, const char *filename) -{ - AVCodec *codec; - AVCodecContext *c= NULL; - int frame_count; - FILE *f; - AVFrame *frame; - uint8_t inbuf[INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE]; - AVPacket avpkt; - - av_init_packet(&avpkt); - - /* set end of buffer to 0 (this ensures that no overreading happens for damaged mpeg streams) */ - memset(inbuf + INBUF_SIZE, 0, FF_INPUT_BUFFER_PADDING_SIZE); - - printf("Decode video file %s to %s\n", filename, outfilename); - - /* find the mpeg1 video decoder */ - codec = avcodec_find_decoder(AV_CODEC_ID_MPEG1VIDEO); - if (!codec) { - fprintf(stderr, "Codec not found\n"); - exit(1); - } - - c = avcodec_alloc_context3(codec); - if (!c) { - fprintf(stderr, "Could not allocate video codec context\n"); - exit(1); - } - - if(codec->capabilities&CODEC_CAP_TRUNCATED) - c->flags|= CODEC_FLAG_TRUNCATED; /* we do not send complete frames */ - - /* For some codecs, such as msmpeg4 and mpeg4, width and height - MUST be initialized there because this information is not - available in the bitstream. */ - - /* open it */ - if (avcodec_open2(c, codec, NULL) < 0) { - fprintf(stderr, "Could not open codec\n"); - exit(1); - } - - f = fopen(filename, "rb"); - if (!f) { - fprintf(stderr, "Could not open %s\n", filename); - exit(1); - } - - frame = av_frame_alloc(); - if (!frame) { - fprintf(stderr, "Could not allocate video frame\n"); - exit(1); - } - - frame_count = 0; - for (;;) { - avpkt.size = fread(inbuf, 1, INBUF_SIZE, f); - if (avpkt.size == 0) - break; - - /* NOTE1: some codecs are stream based (mpegvideo, mpegaudio) - and this is the only method to use them because you cannot - know the compressed data size before analysing it. - - BUT some other codecs (msmpeg4, mpeg4) are inherently frame - based, so you must call them with all the data for one - frame exactly. You must also initialize 'width' and - 'height' before initializing them. */ - - /* NOTE2: some codecs allow the raw parameters (frame size, - sample rate) to be changed at any frame. We handle this, so - you should also take care of it */ - - /* here, we use a stream based decoder (mpeg1video), so we - feed decoder and see if it could decode a frame */ - avpkt.data = inbuf; - while (avpkt.size > 0) - if (decode_write_frame(outfilename, c, frame, &frame_count, &avpkt, 0) < 0) - exit(1); - } - - /* some codecs, such as MPEG, transmit the I and P frame with a - latency of one frame. You must do the following to have a - chance to get the last frame of the video */ - avpkt.data = NULL; - avpkt.size = 0; - decode_write_frame(outfilename, c, frame, &frame_count, &avpkt, 1); - - fclose(f); - - avcodec_close(c); - av_free(c); - av_frame_free(&frame); - printf("\n"); -} - -int main(int argc, char **argv) -{ - const char *output_type; - - /* register all the codecs */ - avcodec_register_all(); - - if (argc < 2) { - printf("usage: %s output_type\n" - "API example program to decode/encode a media stream with libavcodec.\n" - "This program generates a synthetic stream and encodes it to a file\n" - "named test.h264, test.mp2 or test.mpg depending on output_type.\n" - "The encoded stream is then decoded and written to a raw data output.\n" - "output_type must be choosen between 'h264', 'mp2', 'mpg'.\n", - argv[0]); - return 1; - } - output_type = argv[1]; - - if (!strcmp(output_type, "h264")) { - video_encode_example("test.h264", AV_CODEC_ID_H264); - } else if (!strcmp(output_type, "mp2")) { - audio_encode_example("test.mp2"); - audio_decode_example("test.sw", "test.mp2"); - } else if (!strcmp(output_type, "mpg")) { - video_encode_example("test.mpg", AV_CODEC_ID_MPEG1VIDEO); - video_decode_example("test%02d.pgm", "test.mpg"); - } else { - fprintf(stderr, "Invalid output type '%s', choose between 'h264', 'mp2', or 'mpg'\n", - output_type); - return 1; - } - - return 0; -} |