[deb_ffmpeg.git] / ffmpeg / doc / examples / transcoding.c

/*
 * Copyright (c) 2010 Nicolas George
 * Copyright (c) 2011 Stefano Sabatini
 * Copyright (c) 2014 Andrey Utkin
 *
 * 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
 * API example for demuxing, decoding, filtering, encoding and muxing
 * @example transcoding.c
 */

#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libavfilter/avfiltergraph.h>
#include <libavfilter/avcodec.h>
#include <libavfilter/buffersink.h>
#include <libavfilter/buffersrc.h>
#include <libavutil/opt.h>
#include <libavutil/pixdesc.h>

static AVFormatContext *ifmt_ctx;
static AVFormatContext *ofmt_ctx;
typedef struct FilteringContext {
    AVFilterContext *buffersink_ctx;
    AVFilterContext *buffersrc_ctx;
    AVFilterGraph *filter_graph;
} FilteringContext;
static FilteringContext *filter_ctx;

static int open_input_file(const char *filename)
{
    int ret;
    unsigned int i;

    ifmt_ctx = NULL;
    if ((ret = avformat_open_input(&ifmt_ctx, filename, NULL, NULL)) < 0) {
        av_log(NULL, AV_LOG_ERROR, "Cannot open input file\n");
        return ret;
    }

    if ((ret = avformat_find_stream_info(ifmt_ctx, NULL)) < 0) {
        av_log(NULL, AV_LOG_ERROR, "Cannot find stream information\n");
        return ret;
    }

    for (i = 0; i < ifmt_ctx->nb_streams; i++) {
        AVStream *stream;
        AVCodecContext *codec_ctx;
        stream = ifmt_ctx->streams[i];
        codec_ctx = stream->codec;
        /* Reencode video & audio and remux subtitles etc. */
        if (codec_ctx->codec_type == AVMEDIA_TYPE_VIDEO
                || codec_ctx->codec_type == AVMEDIA_TYPE_AUDIO) {
            /* Open decoder */
            ret = avcodec_open2(codec_ctx,
                    avcodec_find_decoder(codec_ctx->codec_id), NULL);
            if (ret < 0) {
                av_log(NULL, AV_LOG_ERROR, "Failed to open decoder for stream #%u\n", i);
                return ret;
            }
        }
    }

    av_dump_format(ifmt_ctx, 0, filename, 0);
    return 0;
}

static int open_output_file(const char *filename)
{
    AVStream *out_stream;
    AVStream *in_stream;
    AVCodecContext *dec_ctx, *enc_ctx;
    AVCodec *encoder;
    int ret;
    unsigned int i;

    ofmt_ctx = NULL;
    avformat_alloc_output_context2(&ofmt_ctx, NULL, NULL, filename);
    if (!ofmt_ctx) {
        av_log(NULL, AV_LOG_ERROR, "Could not create output context\n");
        return AVERROR_UNKNOWN;
    }


    for (i = 0; i < ifmt_ctx->nb_streams; i++) {
        out_stream = avformat_new_stream(ofmt_ctx, NULL);
        if (!out_stream) {
            av_log(NULL, AV_LOG_ERROR, "Failed allocating output stream\n");
            return AVERROR_UNKNOWN;
        }

        in_stream = ifmt_ctx->streams[i];
        dec_ctx = in_stream->codec;
        enc_ctx = out_stream->codec;

        if (dec_ctx->codec_type == AVMEDIA_TYPE_VIDEO
                || dec_ctx->codec_type == AVMEDIA_TYPE_AUDIO) {
            /* in this example, we choose transcoding to same codec */
            encoder = avcodec_find_encoder(dec_ctx->codec_id);

            /* In this example, we transcode to same properties (picture size,
             * sample rate etc.). These properties can be changed for output
             * streams easily using filters */
            if (dec_ctx->codec_type == AVMEDIA_TYPE_VIDEO) {
                enc_ctx->height = dec_ctx->height;
                enc_ctx->width = dec_ctx->width;
                enc_ctx->sample_aspect_ratio = dec_ctx->sample_aspect_ratio;
                /* take first format from list of supported formats */
                enc_ctx->pix_fmt = encoder->pix_fmts[0];
                /* video time_base can be set to whatever is handy and supported by encoder */
                enc_ctx->time_base = dec_ctx->time_base;
            } else {
                enc_ctx->sample_rate = dec_ctx->sample_rate;
                enc_ctx->channel_layout = dec_ctx->channel_layout;
                enc_ctx->channels = av_get_channel_layout_nb_channels(enc_ctx->channel_layout);
                /* take first format from list of supported formats */
                enc_ctx->sample_fmt = encoder->sample_fmts[0];
                enc_ctx->time_base = (AVRational){1, enc_ctx->sample_rate};
            }

            /* Third parameter can be used to pass settings to encoder */
            ret = avcodec_open2(enc_ctx, encoder, NULL);
            if (ret < 0) {
                av_log(NULL, AV_LOG_ERROR, "Cannot open video encoder for stream #%u\n", i);
                return ret;
            }
        } else if (dec_ctx->codec_type == AVMEDIA_TYPE_UNKNOWN) {
            av_log(NULL, AV_LOG_FATAL, "Elementary stream #%d is of unknown type, cannot proceed\n", i);
            return AVERROR_INVALIDDATA;
        } else {
            /* if this stream must be remuxed */
            ret = avcodec_copy_context(ofmt_ctx->streams[i]->codec,
                    ifmt_ctx->streams[i]->codec);
            if (ret < 0) {
                av_log(NULL, AV_LOG_ERROR, "Copying stream context failed\n");
                return ret;
            }
        }

        if (ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER)
            enc_ctx->flags |= CODEC_FLAG_GLOBAL_HEADER;

    }
    av_dump_format(ofmt_ctx, 0, filename, 1);

    if (!(ofmt_ctx->oformat->flags & AVFMT_NOFILE)) {
        ret = avio_open(&ofmt_ctx->pb, filename, AVIO_FLAG_WRITE);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Could not open output file '%s'", filename);
            return ret;
        }
    }

    /* init muxer, write output file header */
    ret = avformat_write_header(ofmt_ctx, NULL);
    if (ret < 0) {
        av_log(NULL, AV_LOG_ERROR, "Error occurred when opening output file\n");
        return ret;
    }

    return 0;
}

static int init_filter(FilteringContext* fctx, AVCodecContext *dec_ctx,
        AVCodecContext *enc_ctx, const char *filter_spec)
{
    char args[512];
    int ret = 0;
    AVFilter *buffersrc = NULL;
    AVFilter *buffersink = NULL;
    AVFilterContext *buffersrc_ctx = NULL;
    AVFilterContext *buffersink_ctx = NULL;
    AVFilterInOut *outputs = avfilter_inout_alloc();
    AVFilterInOut *inputs  = avfilter_inout_alloc();
    AVFilterGraph *filter_graph = avfilter_graph_alloc();

    if (!outputs || !inputs || !filter_graph) {
        ret = AVERROR(ENOMEM);
        goto end;
    }

    if (dec_ctx->codec_type == AVMEDIA_TYPE_VIDEO) {
        buffersrc = avfilter_get_by_name("buffer");
        buffersink = avfilter_get_by_name("buffersink");
        if (!buffersrc || !buffersink) {
            av_log(NULL, AV_LOG_ERROR, "filtering source or sink element not found\n");
            ret = AVERROR_UNKNOWN;
            goto end;
        }

        snprintf(args, sizeof(args),
                "video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d",
                dec_ctx->width, dec_ctx->height, dec_ctx->pix_fmt,
                dec_ctx->time_base.num, dec_ctx->time_base.den,
                dec_ctx->sample_aspect_ratio.num,
                dec_ctx->sample_aspect_ratio.den);

        ret = avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in",
                args, NULL, filter_graph);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Cannot create buffer source\n");
            goto end;
        }

        ret = avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out",
                NULL, NULL, filter_graph);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Cannot create buffer sink\n");
            goto end;
        }

        ret = av_opt_set_bin(buffersink_ctx, "pix_fmts",
                (uint8_t*)&enc_ctx->pix_fmt, sizeof(enc_ctx->pix_fmt),
                AV_OPT_SEARCH_CHILDREN);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Cannot set output pixel format\n");
            goto end;
        }
    } else if (dec_ctx->codec_type == AVMEDIA_TYPE_AUDIO) {
        buffersrc = avfilter_get_by_name("abuffer");
        buffersink = avfilter_get_by_name("abuffersink");
        if (!buffersrc || !buffersink) {
            av_log(NULL, AV_LOG_ERROR, "filtering source or sink element not found\n");
            ret = AVERROR_UNKNOWN;
            goto end;
        }

        if (!dec_ctx->channel_layout)
            dec_ctx->channel_layout =
                av_get_default_channel_layout(dec_ctx->channels);
        snprintf(args, sizeof(args),
                "time_base=%d/%d:sample_rate=%d:sample_fmt=%s:channel_layout=0x%"PRIx64,
                dec_ctx->time_base.num, dec_ctx->time_base.den, dec_ctx->sample_rate,
                av_get_sample_fmt_name(dec_ctx->sample_fmt),
                dec_ctx->channel_layout);
        ret = avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in",
                args, NULL, filter_graph);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Cannot create audio buffer source\n");
            goto end;
        }

        ret = avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out",
                NULL, NULL, filter_graph);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Cannot create audio buffer sink\n");
            goto end;
        }

        ret = av_opt_set_bin(buffersink_ctx, "sample_fmts",
                (uint8_t*)&enc_ctx->sample_fmt, sizeof(enc_ctx->sample_fmt),
                AV_OPT_SEARCH_CHILDREN);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Cannot set output sample format\n");
            goto end;
        }

        ret = av_opt_set_bin(buffersink_ctx, "channel_layouts",
                (uint8_t*)&enc_ctx->channel_layout,
                sizeof(enc_ctx->channel_layout), AV_OPT_SEARCH_CHILDREN);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Cannot set output channel layout\n");
            goto end;
        }

        ret = av_opt_set_bin(buffersink_ctx, "sample_rates",
                (uint8_t*)&enc_ctx->sample_rate, sizeof(enc_ctx->sample_rate),
                AV_OPT_SEARCH_CHILDREN);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Cannot set output sample rate\n");
            goto end;
        }
    } else {
        ret = AVERROR_UNKNOWN;
        goto end;
    }

    /* Endpoints for the filter graph. */
    outputs->name       = av_strdup("in");
    outputs->filter_ctx = buffersrc_ctx;
    outputs->pad_idx    = 0;
    outputs->next       = NULL;

    inputs->name       = av_strdup("out");
    inputs->filter_ctx = buffersink_ctx;
    inputs->pad_idx    = 0;
    inputs->next       = NULL;

    if (!outputs->name || !inputs->name) {
        ret = AVERROR(ENOMEM);
        goto end;
    }

    if ((ret = avfilter_graph_parse_ptr(filter_graph, filter_spec,
                    &inputs, &outputs, NULL)) < 0)
        goto end;

    if ((ret = avfilter_graph_config(filter_graph, NULL)) < 0)
        goto end;

    /* Fill FilteringContext */
    fctx->buffersrc_ctx = buffersrc_ctx;
    fctx->buffersink_ctx = buffersink_ctx;
    fctx->filter_graph = filter_graph;

end:
    avfilter_inout_free(&inputs);
    avfilter_inout_free(&outputs);

    return ret;
}

static int init_filters(void)
{
    const char *filter_spec;
    unsigned int i;
    int ret;
    filter_ctx = av_malloc_array(ifmt_ctx->nb_streams, sizeof(*filter_ctx));
    if (!filter_ctx)
        return AVERROR(ENOMEM);

    for (i = 0; i < ifmt_ctx->nb_streams; i++) {
        filter_ctx[i].buffersrc_ctx  = NULL;
        filter_ctx[i].buffersink_ctx = NULL;
        filter_ctx[i].filter_graph   = NULL;
        if (!(ifmt_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_AUDIO
                || ifmt_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO))
            continue;


        if (ifmt_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO)
            filter_spec = "null"; /* passthrough (dummy) filter for video */
        else
            filter_spec = "anull"; /* passthrough (dummy) filter for audio */
        ret = init_filter(&filter_ctx[i], ifmt_ctx->streams[i]->codec,
                ofmt_ctx->streams[i]->codec, filter_spec);
        if (ret)
            return ret;
    }
    return 0;
}

static int encode_write_frame(AVFrame *filt_frame, unsigned int stream_index, int *got_frame) {
    int ret;
    int got_frame_local;
    AVPacket enc_pkt;
    int (*enc_func)(AVCodecContext *, AVPacket *, const AVFrame *, int *) =
        (ifmt_ctx->streams[stream_index]->codec->codec_type ==
         AVMEDIA_TYPE_VIDEO) ? avcodec_encode_video2 : avcodec_encode_audio2;

    if (!got_frame)
        got_frame = &got_frame_local;

    av_log(NULL, AV_LOG_INFO, "Encoding frame\n");
    /* encode filtered frame */
    enc_pkt.data = NULL;
    enc_pkt.size = 0;
    av_init_packet(&enc_pkt);
    ret = enc_func(ofmt_ctx->streams[stream_index]->codec, &enc_pkt,
            filt_frame, got_frame);
    av_frame_free(&filt_frame);
    if (ret < 0)
        return ret;
    if (!(*got_frame))
        return 0;

    /* prepare packet for muxing */
    enc_pkt.stream_index = stream_index;
    av_packet_rescale_ts(&enc_pkt,
                         ofmt_ctx->streams[stream_index]->codec->time_base,
                         ofmt_ctx->streams[stream_index]->time_base);

    av_log(NULL, AV_LOG_DEBUG, "Muxing frame\n");
    /* mux encoded frame */
    ret = av_interleaved_write_frame(ofmt_ctx, &enc_pkt);
    return ret;
}

static int filter_encode_write_frame(AVFrame *frame, unsigned int stream_index)
{
    int ret;
    AVFrame *filt_frame;

    av_log(NULL, AV_LOG_INFO, "Pushing decoded frame to filters\n");
    /* push the decoded frame into the filtergraph */
    ret = av_buffersrc_add_frame_flags(filter_ctx[stream_index].buffersrc_ctx,
            frame, 0);
    if (ret < 0) {
        av_log(NULL, AV_LOG_ERROR, "Error while feeding the filtergraph\n");
        return ret;
    }

    /* pull filtered frames from the filtergraph */
    while (1) {
        filt_frame = av_frame_alloc();
        if (!filt_frame) {
            ret = AVERROR(ENOMEM);
            break;
        }
        av_log(NULL, AV_LOG_INFO, "Pulling filtered frame from filters\n");
        ret = av_buffersink_get_frame(filter_ctx[stream_index].buffersink_ctx,
                filt_frame);
        if (ret < 0) {
            /* if no more frames for output - returns AVERROR(EAGAIN)
             * if flushed and no more frames for output - returns AVERROR_EOF
             * rewrite retcode to 0 to show it as normal procedure completion
             */
            if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
                ret = 0;
            av_frame_free(&filt_frame);
            break;
        }

        filt_frame->pict_type = AV_PICTURE_TYPE_NONE;
        ret = encode_write_frame(filt_frame, stream_index, NULL);
        if (ret < 0)
            break;
    }

    return ret;
}

static int flush_encoder(unsigned int stream_index)
{
    int ret;
    int got_frame;

    if (!(ofmt_ctx->streams[stream_index]->codec->codec->capabilities &
                CODEC_CAP_DELAY))
        return 0;

    while (1) {
        av_log(NULL, AV_LOG_INFO, "Flushing stream #%u encoder\n", stream_index);
        ret = encode_write_frame(NULL, stream_index, &got_frame);
        if (ret < 0)
            break;
        if (!got_frame)
            return 0;
    }
    return ret;
}

int main(int argc, char **argv)
{
    int ret;
    AVPacket packet = { .data = NULL, .size = 0 };
    AVFrame *frame = NULL;
    enum AVMediaType type;
    unsigned int stream_index;
    unsigned int i;
    int got_frame;
    int (*dec_func)(AVCodecContext *, AVFrame *, int *, const AVPacket *);

    if (argc != 3) {
        av_log(NULL, AV_LOG_ERROR, "Usage: %s <input file> <output file>\n", argv[0]);
        return 1;
    }

    av_register_all();
    avfilter_register_all();

    if ((ret = open_input_file(argv[1])) < 0)
        goto end;
    if ((ret = open_output_file(argv[2])) < 0)
        goto end;
    if ((ret = init_filters()) < 0)
        goto end;

    /* read all packets */
    while (1) {
        if ((ret = av_read_frame(ifmt_ctx, &packet)) < 0)
            break;
        stream_index = packet.stream_index;
        type = ifmt_ctx->streams[packet.stream_index]->codec->codec_type;
        av_log(NULL, AV_LOG_DEBUG, "Demuxer gave frame of stream_index %u\n",
                stream_index);

        if (filter_ctx[stream_index].filter_graph) {
            av_log(NULL, AV_LOG_DEBUG, "Going to reencode&filter the frame\n");
            frame = av_frame_alloc();
            if (!frame) {
                ret = AVERROR(ENOMEM);
                break;
            }
            av_packet_rescale_ts(&packet,
                                 ifmt_ctx->streams[stream_index]->time_base,
                                 ifmt_ctx->streams[stream_index]->codec->time_base);
            dec_func = (type == AVMEDIA_TYPE_VIDEO) ? avcodec_decode_video2 :
                avcodec_decode_audio4;
            ret = dec_func(ifmt_ctx->streams[stream_index]->codec, frame,
                    &got_frame, &packet);
            if (ret < 0) {
                av_frame_free(&frame);
                av_log(NULL, AV_LOG_ERROR, "Decoding failed\n");
                break;
            }

            if (got_frame) {
                frame->pts = av_frame_get_best_effort_timestamp(frame);
                ret = filter_encode_write_frame(frame, stream_index);
                av_frame_free(&frame);
                if (ret < 0)
                    goto end;
            } else {
                av_frame_free(&frame);
            }
        } else {
            /* remux this frame without reencoding */
            av_packet_rescale_ts(&packet,
                                 ifmt_ctx->streams[stream_index]->time_base,
                                 ofmt_ctx->streams[stream_index]->time_base);

            ret = av_interleaved_write_frame(ofmt_ctx, &packet);
            if (ret < 0)
                goto end;
        }
        av_free_packet(&packet);
    }

    /* flush filters and encoders */
    for (i = 0; i < ifmt_ctx->nb_streams; i++) {
        /* flush filter */
        if (!filter_ctx[i].filter_graph)
            continue;
        ret = filter_encode_write_frame(NULL, i);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Flushing filter failed\n");
            goto end;
        }

        /* flush encoder */
        ret = flush_encoder(i);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Flushing encoder failed\n");
            goto end;
        }
    }

    av_write_trailer(ofmt_ctx);
end:
    av_free_packet(&packet);
    av_frame_free(&frame);
    for (i = 0; i < ifmt_ctx->nb_streams; i++) {
        avcodec_close(ifmt_ctx->streams[i]->codec);
        if (ofmt_ctx && ofmt_ctx->nb_streams > i && ofmt_ctx->streams[i] && ofmt_ctx->streams[i]->codec)
            avcodec_close(ofmt_ctx->streams[i]->codec);
        if (filter_ctx && filter_ctx[i].filter_graph)
            avfilter_graph_free(&filter_ctx[i].filter_graph);
    }
    av_free(filter_ctx);
    avformat_close_input(&ifmt_ctx);
    if (ofmt_ctx && !(ofmt_ctx->oformat->flags & AVFMT_NOFILE))
        avio_close(ofmt_ctx->pb);
    avformat_free_context(ofmt_ctx);

    if (ret < 0)
        av_log(NULL, AV_LOG_ERROR, "Error occurred: %s\n", av_err2str(ret));

    return ret ? 1 : 0;
}
Commit	Line	Data
2ba45a60 DM	1	/*
	2	* Copyright (c) 2010 Nicolas George
	3	* Copyright (c) 2011 Stefano Sabatini
	4	* Copyright (c) 2014 Andrey Utkin
	5	*
	6	* Permission is hereby granted, free of charge, to any person obtaining a copy
	7	* of this software and associated documentation files (the "Software"), to deal
	8	* in the Software without restriction, including without limitation the rights
	9	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	10	* copies of the Software, and to permit persons to whom the Software is
	11	* furnished to do so, subject to the following conditions:
	12	*
	13	* The above copyright notice and this permission notice shall be included in
	14	* all copies or substantial portions of the Software.
	15	*
	16	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	17	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	18	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	19	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	20	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	21	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	22	* THE SOFTWARE.
	23	*/
	24
	25	/**
	26	* @file
	27	* API example for demuxing, decoding, filtering, encoding and muxing
	28	* @example transcoding.c
	29	*/
	30
	31	#include <libavcodec/avcodec.h>
	32	#include <libavformat/avformat.h>
	33	#include <libavfilter/avfiltergraph.h>
	34	#include <libavfilter/avcodec.h>
	35	#include <libavfilter/buffersink.h>
	36	#include <libavfilter/buffersrc.h>
	37	#include <libavutil/opt.h>
	38	#include <libavutil/pixdesc.h>
	39
	40	static AVFormatContext *ifmt_ctx;
	41	static AVFormatContext *ofmt_ctx;
	42	typedef struct FilteringContext {
	43	AVFilterContext *buffersink_ctx;
	44	AVFilterContext *buffersrc_ctx;
	45	AVFilterGraph *filter_graph;
	46	} FilteringContext;
	47	static FilteringContext *filter_ctx;
	48
	49	static int open_input_file(const char *filename)
	50	{
	51	int ret;
	52	unsigned int i;
	53
	54	ifmt_ctx = NULL;
	55	if ((ret = avformat_open_input(&ifmt_ctx, filename, NULL, NULL)) < 0) {
	56	av_log(NULL, AV_LOG_ERROR, "Cannot open input file\n");
	57	return ret;
	58	}
	59
	60	if ((ret = avformat_find_stream_info(ifmt_ctx, NULL)) < 0) {
	61	av_log(NULL, AV_LOG_ERROR, "Cannot find stream information\n");
	62	return ret;
	63	}
	64
65	for (i = 0; i < ifmt_ctx->nb_streams; i++) {
66	AVStream *stream;
67	AVCodecContext *codec_ctx;
68	stream = ifmt_ctx->streams[i];
69	codec_ctx = stream->codec;
70	/* Reencode video & audio and remux subtitles etc. */
71	if (codec_ctx->codec_type == AVMEDIA_TYPE_VIDEO
72	\|\| codec_ctx->codec_type == AVMEDIA_TYPE_AUDIO) {
73	/* Open decoder */
74	ret = avcodec_open2(codec_ctx,
75	avcodec_find_decoder(codec_ctx->codec_id), NULL);
76	if (ret < 0) {
77	av_log(NULL, AV_LOG_ERROR, "Failed to open decoder for stream #%u\n", i);
78	return ret;
79	}
80	}
81	}
82
83	av_dump_format(ifmt_ctx, 0, filename, 0);
84	return 0;
85	}
86
87	static int open_output_file(const char *filename)
88	{
89	AVStream *out_stream;
90	AVStream *in_stream;
91	AVCodecContext dec_ctx, enc_ctx;
92	AVCodec *encoder;
93	int ret;
94	unsigned int i;
95
96	ofmt_ctx = NULL;
97	avformat_alloc_output_context2(&ofmt_ctx, NULL, NULL, filename);
98	if (!ofmt_ctx) {
99	av_log(NULL, AV_LOG_ERROR, "Could not create output context\n");
100	return AVERROR_UNKNOWN;
101	}
102
103
104	for (i = 0; i < ifmt_ctx->nb_streams; i++) {
105	out_stream = avformat_new_stream(ofmt_ctx, NULL);
106	if (!out_stream) {
107	av_log(NULL, AV_LOG_ERROR, "Failed allocating output stream\n");
108	return AVERROR_UNKNOWN;
109	}
110
111	in_stream = ifmt_ctx->streams[i];
112	dec_ctx = in_stream->codec;
113	enc_ctx = out_stream->codec;
114
115	if (dec_ctx->codec_type == AVMEDIA_TYPE_VIDEO
116	\|\| dec_ctx->codec_type == AVMEDIA_TYPE_AUDIO) {
117	/* in this example, we choose transcoding to same codec */
118	encoder = avcodec_find_encoder(dec_ctx->codec_id);
119
120	/* In this example, we transcode to same properties (picture size,
121	* sample rate etc.). These properties can be changed for output
122	* streams easily using filters */
123	if (dec_ctx->codec_type == AVMEDIA_TYPE_VIDEO) {
124	enc_ctx->height = dec_ctx->height;
125	enc_ctx->width = dec_ctx->width;
126	enc_ctx->sample_aspect_ratio = dec_ctx->sample_aspect_ratio;
127	/* take first format from list of supported formats */
128	enc_ctx->pix_fmt = encoder->pix_fmts[0];
129	/* video time_base can be set to whatever is handy and supported by encoder */
130	enc_ctx->time_base = dec_ctx->time_base;
131	} else {
132	enc_ctx->sample_rate = dec_ctx->sample_rate;
133	enc_ctx->channel_layout = dec_ctx->channel_layout;
134	enc_ctx->channels = av_get_channel_layout_nb_channels(enc_ctx->channel_layout);
135	/* take first format from list of supported formats */
136	enc_ctx->sample_fmt = encoder->sample_fmts[0];
137	enc_ctx->time_base = (AVRational){1, enc_ctx->sample_rate};
138	}
139
140	/* Third parameter can be used to pass settings to encoder */
141	ret = avcodec_open2(enc_ctx, encoder, NULL);
142	if (ret < 0) {
143	av_log(NULL, AV_LOG_ERROR, "Cannot open video encoder for stream #%u\n", i);
144	return ret;
145	}
146	} else if (dec_ctx->codec_type == AVMEDIA_TYPE_UNKNOWN) {
147	av_log(NULL, AV_LOG_FATAL, "Elementary stream #%d is of unknown type, cannot proceed\n", i);
148	return AVERROR_INVALIDDATA;
149	} else {
150	/* if this stream must be remuxed */
151	ret = avcodec_copy_context(ofmt_ctx->streams[i]->codec,
152	ifmt_ctx->streams[i]->codec);
153	if (ret < 0) {
154	av_log(NULL, AV_LOG_ERROR, "Copying stream context failed\n");
155	return ret;
156	}
157	}
158
159	if (ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER)
160	enc_ctx->flags \|= CODEC_FLAG_GLOBAL_HEADER;
161
162	}
163	av_dump_format(ofmt_ctx, 0, filename, 1);
164
165	if (!(ofmt_ctx->oformat->flags & AVFMT_NOFILE)) {
166	ret = avio_open(&ofmt_ctx->pb, filename, AVIO_FLAG_WRITE);
167	if (ret < 0) {
168	av_log(NULL, AV_LOG_ERROR, "Could not open output file '%s'", filename);
169	return ret;
170	}
171	}
172
173	/* init muxer, write output file header */
174	ret = avformat_write_header(ofmt_ctx, NULL);
175	if (ret < 0) {
176	av_log(NULL, AV_LOG_ERROR, "Error occurred when opening output file\n");
177	return ret;
178	}
179
180	return 0;
181	}
182
183	static int init_filter(FilteringContext* fctx, AVCodecContext *dec_ctx,
184	AVCodecContext enc_ctx, const char filter_spec)
185	{
186	char args[512];
187	int ret = 0;
188	AVFilter *buffersrc = NULL;
189	AVFilter *buffersink = NULL;
190	AVFilterContext *buffersrc_ctx = NULL;
191	AVFilterContext *buffersink_ctx = NULL;
192	AVFilterInOut *outputs = avfilter_inout_alloc();
193	AVFilterInOut *inputs = avfilter_inout_alloc();
194	AVFilterGraph *filter_graph = avfilter_graph_alloc();
195
196	if (!outputs \|\| !inputs \|\| !filter_graph) {
197	ret = AVERROR(ENOMEM);
198	goto end;
199	}
200
201	if (dec_ctx->codec_type == AVMEDIA_TYPE_VIDEO) {
202	buffersrc = avfilter_get_by_name("buffer");
203	buffersink = avfilter_get_by_name("buffersink");
204	if (!buffersrc \|\| !buffersink) {
205	av_log(NULL, AV_LOG_ERROR, "filtering source or sink element not found\n");
206	ret = AVERROR_UNKNOWN;
207	goto end;
208	}
209
210	snprintf(args, sizeof(args),
211	"video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d",
212	dec_ctx->width, dec_ctx->height, dec_ctx->pix_fmt,
213	dec_ctx->time_base.num, dec_ctx->time_base.den,
214	dec_ctx->sample_aspect_ratio.num,
215	dec_ctx->sample_aspect_ratio.den);
216
217	ret = avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in",
218	args, NULL, filter_graph);
219	if (ret < 0) {
220	av_log(NULL, AV_LOG_ERROR, "Cannot create buffer source\n");
221	goto end;
222	}
223
224	ret = avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out",
225	NULL, NULL, filter_graph);
226	if (ret < 0) {
227	av_log(NULL, AV_LOG_ERROR, "Cannot create buffer sink\n");
228	goto end;
229	}
230
231	ret = av_opt_set_bin(buffersink_ctx, "pix_fmts",
232	(uint8_t*)&enc_ctx->pix_fmt, sizeof(enc_ctx->pix_fmt),
233	AV_OPT_SEARCH_CHILDREN);
234	if (ret < 0) {
235	av_log(NULL, AV_LOG_ERROR, "Cannot set output pixel format\n");
236	goto end;
237	}
238	} else if (dec_ctx->codec_type == AVMEDIA_TYPE_AUDIO) {
239	buffersrc = avfilter_get_by_name("abuffer");
240	buffersink = avfilter_get_by_name("abuffersink");
241	if (!buffersrc \|\| !buffersink) {
242	av_log(NULL, AV_LOG_ERROR, "filtering source or sink element not found\n");
243	ret = AVERROR_UNKNOWN;
244	goto end;
245	}
246
247	if (!dec_ctx->channel_layout)
248	dec_ctx->channel_layout =
249	av_get_default_channel_layout(dec_ctx->channels);
250	snprintf(args, sizeof(args),
251	"time_base=%d/%d:sample_rate=%d:sample_fmt=%s:channel_layout=0x%"PRIx64,
252	dec_ctx->time_base.num, dec_ctx->time_base.den, dec_ctx->sample_rate,
253	av_get_sample_fmt_name(dec_ctx->sample_fmt),
254	dec_ctx->channel_layout);
255	ret = avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in",
256	args, NULL, filter_graph);
257	if (ret < 0) {
258	av_log(NULL, AV_LOG_ERROR, "Cannot create audio buffer source\n");
259	goto end;
260	}
261
262	ret = avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out",
263	NULL, NULL, filter_graph);
264	if (ret < 0) {
265	av_log(NULL, AV_LOG_ERROR, "Cannot create audio buffer sink\n");
266	goto end;
267	}
268
269	ret = av_opt_set_bin(buffersink_ctx, "sample_fmts",
270	(uint8_t*)&enc_ctx->sample_fmt, sizeof(enc_ctx->sample_fmt),
271	AV_OPT_SEARCH_CHILDREN);
272	if (ret < 0) {
273	av_log(NULL, AV_LOG_ERROR, "Cannot set output sample format\n");
274	goto end;
275	}
276
277	ret = av_opt_set_bin(buffersink_ctx, "channel_layouts",
278	(uint8_t*)&enc_ctx->channel_layout,
279	sizeof(enc_ctx->channel_layout), AV_OPT_SEARCH_CHILDREN);
280	if (ret < 0) {
281	av_log(NULL, AV_LOG_ERROR, "Cannot set output channel layout\n");
282	goto end;
283	}
284
285	ret = av_opt_set_bin(buffersink_ctx, "sample_rates",
286	(uint8_t*)&enc_ctx->sample_rate, sizeof(enc_ctx->sample_rate),
287	AV_OPT_SEARCH_CHILDREN);
288	if (ret < 0) {
289	av_log(NULL, AV_LOG_ERROR, "Cannot set output sample rate\n");
290	goto end;
291	}
292	} else {
293	ret = AVERROR_UNKNOWN;
294	goto end;
295	}
296
297	/* Endpoints for the filter graph. */
298	outputs->name = av_strdup("in");
299	outputs->filter_ctx = buffersrc_ctx;
300	outputs->pad_idx = 0;
301	outputs->next = NULL;
302
303	inputs->name = av_strdup("out");
304	inputs->filter_ctx = buffersink_ctx;
305	inputs->pad_idx = 0;
306	inputs->next = NULL;
307
308	if (!outputs->name \|\| !inputs->name) {
309	ret = AVERROR(ENOMEM);
310	goto end;
311	}
312
313	if ((ret = avfilter_graph_parse_ptr(filter_graph, filter_spec,
314	&inputs, &outputs, NULL)) < 0)
315	goto end;
316
317	if ((ret = avfilter_graph_config(filter_graph, NULL)) < 0)
318	goto end;
319
320	/* Fill FilteringContext */
321	fctx->buffersrc_ctx = buffersrc_ctx;
322	fctx->buffersink_ctx = buffersink_ctx;
323	fctx->filter_graph = filter_graph;
324
325	end:
326	avfilter_inout_free(&inputs);
327	avfilter_inout_free(&outputs);
328
329	return ret;
330	}
331
332	static int init_filters(void)
333	{
334	const char *filter_spec;
335	unsigned int i;
336	int ret;
337	filter_ctx = av_malloc_array(ifmt_ctx->nb_streams, sizeof(*filter_ctx));
338	if (!filter_ctx)
339	return AVERROR(ENOMEM);
340
341	for (i = 0; i < ifmt_ctx->nb_streams; i++) {
342	filter_ctx[i].buffersrc_ctx = NULL;
343	filter_ctx[i].buffersink_ctx = NULL;
344	filter_ctx[i].filter_graph = NULL;
345	if (!(ifmt_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_AUDIO
346	\|\| ifmt_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO))
347	continue;
348
349
350	if (ifmt_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO)
351	filter_spec = "null"; /* passthrough (dummy) filter for video */
352	else
353	filter_spec = "anull"; /* passthrough (dummy) filter for audio */
354	ret = init_filter(&filter_ctx[i], ifmt_ctx->streams[i]->codec,
355	ofmt_ctx->streams[i]->codec, filter_spec);
356	if (ret)
357	return ret;
358	}
359	return 0;
360	}
361
362	static int encode_write_frame(AVFrame filt_frame, unsigned int stream_index, int got_frame) {
363	int ret;
364	int got_frame_local;
365	AVPacket enc_pkt;
366	int (enc_func)(AVCodecContext , AVPacket , const AVFrame , int *) =
367	(ifmt_ctx->streams[stream_index]->codec->codec_type ==
368	AVMEDIA_TYPE_VIDEO) ? avcodec_encode_video2 : avcodec_encode_audio2;
369
370	if (!got_frame)
371	got_frame = &got_frame_local;
372
373	av_log(NULL, AV_LOG_INFO, "Encoding frame\n");
374	/* encode filtered frame */
375	enc_pkt.data = NULL;
376	enc_pkt.size = 0;
377	av_init_packet(&enc_pkt);
378	ret = enc_func(ofmt_ctx->streams[stream_index]->codec, &enc_pkt,
379	filt_frame, got_frame);
380	av_frame_free(&filt_frame);
381	if (ret < 0)
382	return ret;
383	if (!(*got_frame))
384	return 0;
385
386	/* prepare packet for muxing */
387	enc_pkt.stream_index = stream_index;
f6fa7814 DM	388	av_packet_rescale_ts(&enc_pkt,
	389	ofmt_ctx->streams[stream_index]->codec->time_base,
	390	ofmt_ctx->streams[stream_index]->time_base);
2ba45a60 DM	391
	392	av_log(NULL, AV_LOG_DEBUG, "Muxing frame\n");
	393	/* mux encoded frame */
	394	ret = av_interleaved_write_frame(ofmt_ctx, &enc_pkt);
	395	return ret;
	396	}
	397
	398	static int filter_encode_write_frame(AVFrame *frame, unsigned int stream_index)
	399	{
	400	int ret;
	401	AVFrame *filt_frame;
	402
	403	av_log(NULL, AV_LOG_INFO, "Pushing decoded frame to filters\n");
	404	/* push the decoded frame into the filtergraph */
	405	ret = av_buffersrc_add_frame_flags(filter_ctx[stream_index].buffersrc_ctx,
	406	frame, 0);
	407	if (ret < 0) {
	408	av_log(NULL, AV_LOG_ERROR, "Error while feeding the filtergraph\n");
	409	return ret;
	410	}
	411
	412	/* pull filtered frames from the filtergraph */
	413	while (1) {
	414	filt_frame = av_frame_alloc();
	415	if (!filt_frame) {
	416	ret = AVERROR(ENOMEM);
	417	break;
	418	}
	419	av_log(NULL, AV_LOG_INFO, "Pulling filtered frame from filters\n");
	420	ret = av_buffersink_get_frame(filter_ctx[stream_index].buffersink_ctx,
	421	filt_frame);
	422	if (ret < 0) {
	423	/* if no more frames for output - returns AVERROR(EAGAIN)
	424	* if flushed and no more frames for output - returns AVERROR_EOF
	425	* rewrite retcode to 0 to show it as normal procedure completion
	426	*/
	427	if (ret == AVERROR(EAGAIN) \|\| ret == AVERROR_EOF)
	428	ret = 0;
	429	av_frame_free(&filt_frame);
	430	break;
	431	}
	432
	433	filt_frame->pict_type = AV_PICTURE_TYPE_NONE;
	434	ret = encode_write_frame(filt_frame, stream_index, NULL);
	435	if (ret < 0)
	436	break;
	437	}
	438
	439	return ret;
	440	}
	441
	442	static int flush_encoder(unsigned int stream_index)
	443	{
	444	int ret;
	445	int got_frame;
	446
	447	if (!(ofmt_ctx->streams[stream_index]->codec->codec->capabilities &
	448	CODEC_CAP_DELAY))
	449	return 0;
	450
	451	while (1) {
	452	av_log(NULL, AV_LOG_INFO, "Flushing stream #%u encoder\n", stream_index);
	453	ret = encode_write_frame(NULL, stream_index, &got_frame);
	454	if (ret < 0)
455	break;
456	if (!got_frame)
457	return 0;
458	}
459	return ret;
460	}
461
462	int main(int argc, char **argv)
463	{
464	int ret;
465	AVPacket packet = { .data = NULL, .size = 0 };
466	AVFrame *frame = NULL;
467	enum AVMediaType type;
468	unsigned int stream_index;
469	unsigned int i;
470	int got_frame;
471	int (dec_func)(AVCodecContext , AVFrame , int , const AVPacket *);
472
473	if (argc != 3) {
474	av_log(NULL, AV_LOG_ERROR, "Usage: %s <input file> <output file>\n", argv[0]);
475	return 1;
476	}
477
478	av_register_all();
479	avfilter_register_all();
480
481	if ((ret = open_input_file(argv[1])) < 0)
482	goto end;
483	if ((ret = open_output_file(argv[2])) < 0)
484	goto end;
485	if ((ret = init_filters()) < 0)
486	goto end;
487
488	/* read all packets */
489	while (1) {
490	if ((ret = av_read_frame(ifmt_ctx, &packet)) < 0)
491	break;
492	stream_index = packet.stream_index;
493	type = ifmt_ctx->streams[packet.stream_index]->codec->codec_type;
494	av_log(NULL, AV_LOG_DEBUG, "Demuxer gave frame of stream_index %u\n",
495	stream_index);
496
497	if (filter_ctx[stream_index].filter_graph) {
498	av_log(NULL, AV_LOG_DEBUG, "Going to reencode&filter the frame\n");
499	frame = av_frame_alloc();
500	if (!frame) {
501	ret = AVERROR(ENOMEM);
502	break;
503	}
f6fa7814 DM	504	av_packet_rescale_ts(&packet,
	505	ifmt_ctx->streams[stream_index]->time_base,
	506	ifmt_ctx->streams[stream_index]->codec->time_base);
2ba45a60 DM	507	dec_func = (type == AVMEDIA_TYPE_VIDEO) ? avcodec_decode_video2 :
	508	avcodec_decode_audio4;
	509	ret = dec_func(ifmt_ctx->streams[stream_index]->codec, frame,
	510	&got_frame, &packet);
	511	if (ret < 0) {
	512	av_frame_free(&frame);
	513	av_log(NULL, AV_LOG_ERROR, "Decoding failed\n");
	514	break;
	515	}
	516
	517	if (got_frame) {
	518	frame->pts = av_frame_get_best_effort_timestamp(frame);
	519	ret = filter_encode_write_frame(frame, stream_index);
	520	av_frame_free(&frame);
	521	if (ret < 0)
	522	goto end;
	523	} else {
	524	av_frame_free(&frame);
	525	}
	526	} else {
	527	/* remux this frame without reencoding */
f6fa7814 DM	528	av_packet_rescale_ts(&packet,
	529	ifmt_ctx->streams[stream_index]->time_base,
	530	ofmt_ctx->streams[stream_index]->time_base);
2ba45a60 DM	531
	532	ret = av_interleaved_write_frame(ofmt_ctx, &packet);
	533	if (ret < 0)
	534	goto end;
	535	}
	536	av_free_packet(&packet);
	537	}
	538
	539	/* flush filters and encoders */
	540	for (i = 0; i < ifmt_ctx->nb_streams; i++) {
	541	/* flush filter */
	542	if (!filter_ctx[i].filter_graph)
	543	continue;
	544	ret = filter_encode_write_frame(NULL, i);
	545	if (ret < 0) {
	546	av_log(NULL, AV_LOG_ERROR, "Flushing filter failed\n");
	547	goto end;
	548	}
	549
	550	/* flush encoder */
	551	ret = flush_encoder(i);
	552	if (ret < 0) {
	553	av_log(NULL, AV_LOG_ERROR, "Flushing encoder failed\n");
	554	goto end;
	555	}
	556	}
	557
	558	av_write_trailer(ofmt_ctx);
	559	end:
	560	av_free_packet(&packet);
	561	av_frame_free(&frame);
	562	for (i = 0; i < ifmt_ctx->nb_streams; i++) {
	563	avcodec_close(ifmt_ctx->streams[i]->codec);
	564	if (ofmt_ctx && ofmt_ctx->nb_streams > i && ofmt_ctx->streams[i] && ofmt_ctx->streams[i]->codec)
	565	avcodec_close(ofmt_ctx->streams[i]->codec);
	566	if (filter_ctx && filter_ctx[i].filter_graph)
	567	avfilter_graph_free(&filter_ctx[i].filter_graph);
	568	}
	569	av_free(filter_ctx);
	570	avformat_close_input(&ifmt_ctx);
	571	if (ofmt_ctx && !(ofmt_ctx->oformat->flags & AVFMT_NOFILE))
	572	avio_close(ofmt_ctx->pb);
	573	avformat_free_context(ofmt_ctx);
	574
	575	if (ret < 0)
	576	av_log(NULL, AV_LOG_ERROR, "Error occurred: %s\n", av_err2str(ret));
	577
	578	return ret ? 1 : 0;
	579	}