/* * Copyright (c) 2012 Stefano Sabatini * * 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 * Demuxing and decoding example. * * Show how to use the libavformat and libavcodec API to demux and * decode audio and video data. * @example demuxing_decoding.c */ #include <libavutil/imgutils.h>#include <libavutil/samplefmt.h>#include <libavutil/timestamp.h>#include <libavformat/avformat.h> static AVFormatContext *fmt_ctx = NULL;static AVCodecContext *video_dec_ctx = NULL, *audio_dec_ctx;static int width, height;static enum AVPixelFormat pix_fmt;static AVStream *video_stream = NULL, *audio_stream = NULL;static const char *src_filename = NULL;static const char *video_dst_filename = NULL;static const char *audio_dst_filename = NULL;static FILE *video_dst_file = NULL;static FILE *audio_dst_file = NULL; static uint8_t *video_dst_data[4] = {NULL};static int      video_dst_linesize[4];static int video_dst_bufsize; static int video_stream_idx = -1, audio_stream_idx = -1;static AVFrame *frame = NULL;static AVPacket pkt;static int video_frame_count = 0;static int audio_frame_count = 0; /* Enable or disable frame reference counting. You are not supposed to support * both paths in your application but pick the one most appropriate to your * needs. Look for the use of refcount in this example to see what are the * differences of API usage between them. */static int refcount = 0; static int decode_packet(int *got_frame, int cached){    int ret = 0;    int decoded = pkt.size;     *got_frame = 0;     if (pkt.stream_index == video_stream_idx) {        /* decode video frame */        ret = avcodec_decode_video2(video_dec_ctx, frame, got_frame, &pkt);        if (ret < 0) {            fprintf(stderr, "Error decoding video frame (%s)\n", av_err2str(ret));            return ret;        }         if (*got_frame) {             if (frame->width != width || frame->height != height ||                frame->format != pix_fmt) {                /* To handle this change, one could call av_image_alloc again and                 * decode the following frames into another rawvideo file. */                fprintf(stderr, "Error: Width, height and pixel format have to be "                        "constant in a rawvideo file, but the width, height or "                        "pixel format of the input video changed:\n"                        "old: width = %d, height = %d, format = %s\n"                        "new: width = %d, height = %d, format = %s\n",                        width, height, av_get_pix_fmt_name(pix_fmt),                        frame->width, frame->height,                        av_get_pix_fmt_name(frame->format));                return -1;            }             printf("video_frame%s n:%d coded_n:%d\n",                   cached ? "(cached)" : "",                   video_frame_count++, frame->coded_picture_number);             /* copy decoded frame to destination buffer:             * this is required since rawvideo expects non aligned data */            av_image_copy(video_dst_data, video_dst_linesize,                          (const uint8_t **)(frame->data), frame->linesize,                          pix_fmt, width, height);             /* write to rawvideo file */            fwrite(video_dst_data[0], 1, video_dst_bufsize, video_dst_file);        }    } else if (pkt.stream_index == audio_stream_idx) {        /* decode audio frame */        ret = avcodec_decode_audio4(audio_dec_ctx, frame, got_frame, &pkt);        if (ret < 0) {            fprintf(stderr, "Error decoding audio frame (%s)\n", av_err2str(ret));            return ret;        }        /* Some audio decoders decode only part of the packet, and have to be         * called again with the remainder of the packet data.         * Sample: fate-suite/lossless-audio/luckynight-partial.shn         * Also, some decoders might over-read the packet. */        decoded = FFMIN(ret, pkt.size);         if (*got_frame) {            size_t unpadded_linesize = frame->nb_samples * av_get_bytes_per_sample(frame->format);            printf("audio_frame%s n:%d nb_samples:%d pts:%s\n",                   cached ? "(cached)" : "",                   audio_frame_count++, frame->nb_samples,                   av_ts2timestr(frame->pts, &audio_dec_ctx->time_base));             /* Write the raw audio data samples of the first plane. This works             * fine for packed formats (e.g. AV_SAMPLE_FMT_S16). However,             * most audio decoders output planar audio, which uses a separate             * plane of audio samples for each channel (e.g. AV_SAMPLE_FMT_S16P).             * In other words, this code will write only the first audio channel             * in these cases.             * You should use libswresample or libavfilter to convert the frame             * to packed data. */            fwrite(frame->extended_data[0], 1, unpadded_linesize, audio_dst_file);        }    }     /* If we use frame reference counting, we own the data and need     * to de-reference it when we don't use it anymore */    if (*got_frame && refcount)        av_frame_unref(frame);     return decoded;} static int open_codec_context(int *stream_idx,                              AVCodecContext **dec_ctx, AVFormatContext *fmt_ctx, enum AVMediaType type){    int ret, stream_index;    AVStream *st;    AVCodec *dec = NULL;    AVDictionary *opts = NULL;     ret = av_find_best_stream(fmt_ctx, type, -1, -1, NULL, 0);    if (ret < 0) {        fprintf(stderr, "Could not find %s stream in input file '%s'\n",                av_get_media_type_string(type), src_filename);        return ret;    } else {        stream_index = ret;        st = fmt_ctx->streams[stream_index];         /* find decoder for the stream */        dec = avcodec_find_decoder(st->codecpar->codec_id);        if (!dec) {            fprintf(stderr, "Failed to find %s codec\n",                    av_get_media_type_string(type));            return AVERROR(EINVAL);        }         /* Allocate a codec context for the decoder */        *dec_ctx = avcodec_alloc_context3(dec);        if (!*dec_ctx) {            fprintf(stderr, "Failed to allocate the %s codec context\n",                    av_get_media_type_string(type));            return AVERROR(ENOMEM);        }         /* Copy codec parameters from input stream to output codec context */        if ((ret = avcodec_parameters_to_context(*dec_ctx, st->codecpar)) < 0) {            fprintf(stderr, "Failed to copy %s codec parameters to decoder context\n",                    av_get_media_type_string(type));            return ret;        }         /* Init the decoders, with or without reference counting */        av_dict_set(&opts, "refcounted_frames", refcount ? "1" : "0", 0);        if ((ret = avcodec_open2(*dec_ctx, dec, &opts)) < 0) {            fprintf(stderr, "Failed to open %s codec\n",                    av_get_media_type_string(type));            return ret;        }        *stream_idx = stream_index;    }     return 0;} static int get_format_from_sample_fmt(const char **fmt,                                      enum AVSampleFormat sample_fmt){    int i;    struct sample_fmt_entry {        enum AVSampleFormat sample_fmt; const char *fmt_be, *fmt_le;    } sample_fmt_entries[] = {        { AV_SAMPLE_FMT_U8,  "u8",    "u8"    },        { AV_SAMPLE_FMT_S16, "s16be", "s16le" },        { AV_SAMPLE_FMT_S32, "s32be", "s32le" },        { AV_SAMPLE_FMT_FLT, "f32be", "f32le" },        { AV_SAMPLE_FMT_DBL, "f64be", "f64le" },    };    *fmt = NULL;     for (i = 0; i < FF_ARRAY_ELEMS(sample_fmt_entries); i++) {        struct sample_fmt_entry *entry = &sample_fmt_entries[i];        if (sample_fmt == entry->sample_fmt) {            *fmt = AV_NE(entry->fmt_be, entry->fmt_le);            return 0;        }    }     fprintf(stderr,            "sample format %s is not supported as output format\n",            av_get_sample_fmt_name(sample_fmt));    return -1;} int main (int argc, char **argv){    int ret = 0, got_frame;     if (argc != 4 && argc != 5) {        fprintf(stderr, "usage: %s [-refcount] input_file video_output_file audio_output_file\n"                "API example program to show how to read frames from an input file.\n"                "This program reads frames from a file, decodes them, and writes decoded\n"                "video frames to a rawvideo file named video_output_file, and decoded\n"                "audio frames to a rawaudio file named audio_output_file.\n\n"                "If the -refcount option is specified, the program use the\n"                "reference counting frame system which allows keeping a copy of\n"                "the data for longer than one decode call.\n"                "\n", argv[0]);        exit(1);    }    if (argc == 5 && !strcmp(argv[1], "-refcount")) {        refcount = 1;        argv++;    }    src_filename = argv[1];    video_dst_filename = argv[2];    audio_dst_filename = argv[3];     /* register all formats and codecs */    av_register_all();     /* open input file, and allocate format context */    if (avformat_open_input(&fmt_ctx, src_filename, NULL, NULL) < 0) {        fprintf(stderr, "Could not open source file %s\n", src_filename);        exit(1);    }     /* retrieve stream information */    if (avformat_find_stream_info(fmt_ctx, NULL) < 0) {        fprintf(stderr, "Could not find stream information\n");        exit(1);    }     if (open_codec_context(&video_stream_idx, &video_dec_ctx, fmt_ctx, AVMEDIA_TYPE_VIDEO) >= 0) {        video_stream = fmt_ctx->streams[video_stream_idx];         video_dst_file = fopen(video_dst_filename, "wb");        if (!video_dst_file) {            fprintf(stderr, "Could not open destination file %s\n", video_dst_filename);            ret = 1;            goto end;        }         /* allocate image where the decoded image will be put */        width = video_dec_ctx->width;        height = video_dec_ctx->height;        pix_fmt = video_dec_ctx->pix_fmt;        ret = av_image_alloc(video_dst_data, video_dst_linesize,                             width, height, pix_fmt, 1);        if (ret < 0) {            fprintf(stderr, "Could not allocate raw video buffer\n");            goto end;        }        video_dst_bufsize = ret;    }     if (open_codec_context(&audio_stream_idx, &audio_dec_ctx, fmt_ctx, AVMEDIA_TYPE_AUDIO) >= 0) {        audio_stream = fmt_ctx->streams[audio_stream_idx];        audio_dst_file = fopen(audio_dst_filename, "wb");        if (!audio_dst_file) {            fprintf(stderr, "Could not open destination file %s\n", audio_dst_filename);            ret = 1;            goto end;        }    }     /* dump input information to stderr */    av_dump_format(fmt_ctx, 0, src_filename, 0);     if (!audio_stream && !video_stream) {        fprintf(stderr, "Could not find audio or video stream in the input, aborting\n");        ret = 1;        goto end;    }     frame = av_frame_alloc();    if (!frame) {        fprintf(stderr, "Could not allocate frame\n");        ret = AVERROR(ENOMEM);        goto end;    }     /* initialize packet, set data to NULL, let the demuxer fill it */    av_init_packet(&pkt);    pkt.data = NULL;    pkt.size = 0;     if (video_stream)        printf("Demuxing video from file '%s' into '%s'\n", src_filename, video_dst_filename);    if (audio_stream)        printf("Demuxing audio from file '%s' into '%s'\n", src_filename, audio_dst_filename);     /* read frames from the file */    while (av_read_frame(fmt_ctx, &pkt) >= 0) {        AVPacket orig_pkt = pkt;        do {            ret = decode_packet(&got_frame, 0);            if (ret < 0)                break;            pkt.data += ret;            pkt.size -= ret;        } while (pkt.size > 0);        av_packet_unref(&orig_pkt);    }     /* flush cached frames */    pkt.data = NULL;    pkt.size = 0;    do {        decode_packet(&got_frame, 1);    } while (got_frame);     printf("Demuxing succeeded.\n");     if (video_stream) {        printf("Play the output video file with the command:\n"               "ffplay -f rawvideo -pix_fmt %s -video_size %dx%d %s\n",               av_get_pix_fmt_name(pix_fmt), width, height,               video_dst_filename);    }     if (audio_stream) {        enum AVSampleFormat sfmt = audio_dec_ctx->sample_fmt;        int n_channels = audio_dec_ctx->channels;        const char *fmt;         if (av_sample_fmt_is_planar(sfmt)) {            const char *packed = av_get_sample_fmt_name(sfmt);            printf("Warning: the sample format the decoder produced is planar "                   "(%s). This example will output the first channel only.\n",                   packed ? packed : "?");            sfmt = av_get_packed_sample_fmt(sfmt);            n_channels = 1;        }         if ((ret = get_format_from_sample_fmt(&fmt, sfmt)) < 0)            goto end;         printf("Play the output audio file with the command:\n"               "ffplay -f %s -ac %d -ar %d %s\n",               fmt, n_channels, audio_dec_ctx->sample_rate,               audio_dst_filename);    } end:    avcodec_free_context(&video_dec_ctx);    avcodec_free_context(&audio_dec_ctx);    avformat_close_input(&fmt_ctx);    if (video_dst_file)        fclose(video_dst_file);    if (audio_dst_file)        fclose(audio_dst_file);    av_frame_free(&frame);    av_free(video_dst_data[0]);     return ret < 0;}