static int nuv_header(AVFormatContext *s) { NUVContext *ctx = s->priv_data; AVIOContext *pb = s->pb; char id_string[12]; double aspect, fps; int is_mythtv, width, height, v_packs, a_packs; AVStream *vst = NULL, *ast = NULL; avio_read(pb, id_string, 12); is_mythtv = !memcmp(id_string, "MythTVVideo", 12); avio_skip(pb, 5); // version string avio_skip(pb, 3); // padding width = avio_rl32(pb); height = avio_rl32(pb); avio_rl32(pb); // unused, "desiredwidth" avio_rl32(pb); // unused, "desiredheight" avio_r8(pb); // 'P' == progressive, 'I' == interlaced avio_skip(pb, 3); // padding aspect = av_int2double(avio_rl64(pb)); if (aspect > 0.9999 && aspect < 1.0001) aspect = 4.0 / 3.0; fps = av_int2double(avio_rl64(pb)); // number of packets per stream type, -1 means unknown, e.g. streaming v_packs = avio_rl32(pb); a_packs = avio_rl32(pb); avio_rl32(pb); // text avio_rl32(pb); // keyframe distance (?) if (v_packs) { vst = avformat_new_stream(s, NULL); if (!vst) return AVERROR(ENOMEM); ctx->v_id = vst->index; vst->codec->codec_type = AVMEDIA_TYPE_VIDEO; vst->codec->codec_id = AV_CODEC_ID_NUV; vst->codec->width = width; vst->codec->height = height; vst->codec->bits_per_coded_sample = 10; vst->sample_aspect_ratio = av_d2q(aspect * height / width, 10000); #if FF_API_R_FRAME_RATE vst->r_frame_rate = #endif vst->avg_frame_rate = av_d2q(fps, 60000); avpriv_set_pts_info(vst, 32, 1, 1000); } else ctx->v_id = -1; if (a_packs) { ast = avformat_new_stream(s, NULL); if (!ast) return AVERROR(ENOMEM); ctx->a_id = ast->index; ast->codec->codec_type = AVMEDIA_TYPE_AUDIO; ast->codec->codec_id = AV_CODEC_ID_PCM_S16LE; ast->codec->channels = 2; ast->codec->channel_layout = AV_CH_LAYOUT_STEREO; ast->codec->sample_rate = 44100; ast->codec->bit_rate = 2 * 2 * 44100 * 8; ast->codec->block_align = 2 * 2; ast->codec->bits_per_coded_sample = 16; avpriv_set_pts_info(ast, 32, 1, 1000); } else ctx->a_id = -1; get_codec_data(pb, vst, ast, is_mythtv); ctx->rtjpg_video = vst && vst->codec->codec_id == AV_CODEC_ID_NUV; return 0; }