Edit File: 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); if (!encoder) { av_log(NULL, AV_LOG_FATAL, "Necessary encoder not found\n"); return AVERROR_INVALIDDATA; } /* 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 |= AV_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 & AV_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_closep(&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; }