1 /*
2 * This file is part of mpv.
3 *
4 * mpv is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * mpv is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with mpv. If not, see <http://www.gnu.org/licenses/>.
16 */
17
18 #include <stdio.h>
19 #include <stdlib.h>
20 #include <unistd.h>
21 #include <stdbool.h>
22 #include <assert.h>
23
24 #include <libavcodec/avcodec.h>
25 #include <libavutil/opt.h>
26 #include <libavutil/common.h>
27 #include <libavutil/intreadwrite.h>
28
29 #include "mpv_talloc.h"
30 #include "audio/aframe.h"
31 #include "audio/fmt-conversion.h"
32 #include "common/av_common.h"
33 #include "common/codecs.h"
34 #include "common/global.h"
35 #include "common/msg.h"
36 #include "demux/packet.h"
37 #include "demux/stheader.h"
38 #include "filters/f_decoder_wrapper.h"
39 #include "filters/filter_internal.h"
40 #include "options/m_config.h"
41 #include "options/options.h"
42
43 struct priv {
44 AVCodecContext *avctx;
45 AVFrame *avframe;
46 struct mp_chmap force_channel_map;
47 uint32_t skip_samples, trim_samples;
48 bool preroll_done;
49 double next_pts;
50 AVRational codec_timebase;
51 struct lavc_state state;
52
53 struct mp_decoder public;
54 };
55
56 #define OPT_BASE_STRUCT struct ad_lavc_params
57 struct ad_lavc_params {
58 float ac3drc;
59 int downmix;
60 int threads;
61 char **avopts;
62 };
63
64 const struct m_sub_options ad_lavc_conf = {
65 .opts = (const m_option_t[]) {
66 {"ac3drc", OPT_FLOAT(ac3drc), M_RANGE(0, 6)},
67 {"downmix", OPT_FLAG(downmix)},
68 {"threads", OPT_INT(threads), M_RANGE(0, 16)},
69 {"o", OPT_KEYVALUELIST(avopts)},
70 {0}
71 },
72 .size = sizeof(struct ad_lavc_params),
73 .defaults = &(const struct ad_lavc_params){
74 .ac3drc = 0,
75 .downmix = 0,
76 .threads = 1,
77 },
78 };
79
init(struct mp_filter * da,struct mp_codec_params * codec,const char * decoder)80 static bool init(struct mp_filter *da, struct mp_codec_params *codec,
81 const char *decoder)
82 {
83 struct priv *ctx = da->priv;
84 struct MPOpts *mpopts = mp_get_config_group(ctx, da->global, &mp_opt_root);
85 struct ad_lavc_params *opts =
86 mp_get_config_group(ctx, da->global, &ad_lavc_conf);
87 AVCodecContext *lavc_context;
88 const AVCodec *lavc_codec;
89
90 ctx->codec_timebase = mp_get_codec_timebase(codec);
91
92 if (codec->force_channels)
93 ctx->force_channel_map = codec->channels;
94
95 lavc_codec = avcodec_find_decoder_by_name(decoder);
96 if (!lavc_codec) {
97 MP_ERR(da, "Cannot find codec '%s' in libavcodec...\n", decoder);
98 return false;
99 }
100
101 lavc_context = avcodec_alloc_context3(lavc_codec);
102 ctx->avctx = lavc_context;
103 ctx->avframe = av_frame_alloc();
104 lavc_context->codec_type = AVMEDIA_TYPE_AUDIO;
105 lavc_context->codec_id = lavc_codec->id;
106 lavc_context->pkt_timebase = ctx->codec_timebase;
107
108 if (opts->downmix && mpopts->audio_output_channels.num_chmaps == 1) {
109 lavc_context->request_channel_layout =
110 mp_chmap_to_lavc(&mpopts->audio_output_channels.chmaps[0]);
111 }
112
113 // Always try to set - option only exists for AC3 at the moment
114 av_opt_set_double(lavc_context, "drc_scale", opts->ac3drc,
115 AV_OPT_SEARCH_CHILDREN);
116
117 // Let decoder add AV_FRAME_DATA_SKIP_SAMPLES.
118 av_opt_set(lavc_context, "flags2", "+skip_manual", AV_OPT_SEARCH_CHILDREN);
119
120 mp_set_avopts(da->log, lavc_context, opts->avopts);
121
122 if (mp_set_avctx_codec_headers(lavc_context, codec) < 0) {
123 MP_ERR(da, "Could not set decoder parameters.\n");
124 return false;
125 }
126
127 mp_set_avcodec_threads(da->log, lavc_context, opts->threads);
128
129 /* open it */
130 if (avcodec_open2(lavc_context, lavc_codec, NULL) < 0) {
131 MP_ERR(da, "Could not open codec.\n");
132 return false;
133 }
134
135 ctx->next_pts = MP_NOPTS_VALUE;
136
137 return true;
138 }
139
destroy(struct mp_filter * da)140 static void destroy(struct mp_filter *da)
141 {
142 struct priv *ctx = da->priv;
143
144 avcodec_free_context(&ctx->avctx);
145 av_frame_free(&ctx->avframe);
146 }
147
reset(struct mp_filter * da)148 static void reset(struct mp_filter *da)
149 {
150 struct priv *ctx = da->priv;
151
152 avcodec_flush_buffers(ctx->avctx);
153 ctx->skip_samples = 0;
154 ctx->trim_samples = 0;
155 ctx->preroll_done = false;
156 ctx->next_pts = MP_NOPTS_VALUE;
157 ctx->state = (struct lavc_state){0};
158 }
159
send_packet(struct mp_filter * da,struct demux_packet * mpkt)160 static int send_packet(struct mp_filter *da, struct demux_packet *mpkt)
161 {
162 struct priv *priv = da->priv;
163 AVCodecContext *avctx = priv->avctx;
164
165 // If the decoder discards the timestamp for some reason, we use the
166 // interpolated PTS. Initialize it so that it works for the initial
167 // packet as well.
168 if (mpkt && priv->next_pts == MP_NOPTS_VALUE)
169 priv->next_pts = mpkt->pts;
170
171 AVPacket pkt;
172 mp_set_av_packet(&pkt, mpkt, &priv->codec_timebase);
173
174 int ret = avcodec_send_packet(avctx, mpkt ? &pkt : NULL);
175 if (ret < 0)
176 MP_ERR(da, "Error decoding audio.\n");
177 return ret;
178 }
179
receive_frame(struct mp_filter * da,struct mp_frame * out)180 static int receive_frame(struct mp_filter *da, struct mp_frame *out)
181 {
182 struct priv *priv = da->priv;
183 AVCodecContext *avctx = priv->avctx;
184
185 int ret = avcodec_receive_frame(avctx, priv->avframe);
186
187 if (ret == AVERROR_EOF) {
188 // If flushing was initialized earlier and has ended now, make it start
189 // over in case we get new packets at some point in the future.
190 // (Dont' reset the filter itself, we want to keep other state.)
191 avcodec_flush_buffers(priv->avctx);
192 return ret;
193 } else if (ret < 0 && ret != AVERROR(EAGAIN)) {
194 MP_ERR(da, "Error decoding audio.\n");
195 }
196
197 if (priv->avframe->flags & AV_FRAME_FLAG_DISCARD)
198 av_frame_unref(priv->avframe);
199
200 if (!priv->avframe->buf[0])
201 return ret;
202
203 double out_pts = mp_pts_from_av(priv->avframe->pts, &priv->codec_timebase);
204
205 struct mp_aframe *mpframe = mp_aframe_from_avframe(priv->avframe);
206 if (!mpframe) {
207 MP_ERR(da, "Converting libavcodec frame to mpv frame failed.\n");
208 return ret;
209 }
210
211 if (priv->force_channel_map.num)
212 mp_aframe_set_chmap(mpframe, &priv->force_channel_map);
213
214 if (out_pts == MP_NOPTS_VALUE)
215 out_pts = priv->next_pts;
216 mp_aframe_set_pts(mpframe, out_pts);
217
218 priv->next_pts = mp_aframe_end_pts(mpframe);
219
220 AVFrameSideData *sd =
221 av_frame_get_side_data(priv->avframe, AV_FRAME_DATA_SKIP_SAMPLES);
222 if (sd && sd->size >= 10) {
223 char *d = sd->data;
224 priv->skip_samples += AV_RL32(d + 0);
225 priv->trim_samples += AV_RL32(d + 4);
226 }
227
228 if (!priv->preroll_done) {
229 // Skip only if this isn't already handled by AV_FRAME_DATA_SKIP_SAMPLES.
230 if (!priv->skip_samples)
231 priv->skip_samples = avctx->delay;
232 priv->preroll_done = true;
233 }
234
235 uint32_t skip = MPMIN(priv->skip_samples, mp_aframe_get_size(mpframe));
236 if (skip) {
237 mp_aframe_skip_samples(mpframe, skip);
238 priv->skip_samples -= skip;
239 }
240 uint32_t trim = MPMIN(priv->trim_samples, mp_aframe_get_size(mpframe));
241 if (trim) {
242 mp_aframe_set_size(mpframe, mp_aframe_get_size(mpframe) - trim);
243 priv->trim_samples -= trim;
244 }
245
246 if (mp_aframe_get_size(mpframe) > 0) {
247 *out = MAKE_FRAME(MP_FRAME_AUDIO, mpframe);
248 } else {
249 talloc_free(mpframe);
250 }
251
252 av_frame_unref(priv->avframe);
253
254 return ret;
255 }
256
process(struct mp_filter * ad)257 static void process(struct mp_filter *ad)
258 {
259 struct priv *priv = ad->priv;
260
261 lavc_process(ad, &priv->state, send_packet, receive_frame);
262 }
263
264 static const struct mp_filter_info ad_lavc_filter = {
265 .name = "ad_lavc",
266 .priv_size = sizeof(struct priv),
267 .process = process,
268 .reset = reset,
269 .destroy = destroy,
270 };
271
create(struct mp_filter * parent,struct mp_codec_params * codec,const char * decoder)272 static struct mp_decoder *create(struct mp_filter *parent,
273 struct mp_codec_params *codec,
274 const char *decoder)
275 {
276 struct mp_filter *da = mp_filter_create(parent, &ad_lavc_filter);
277 if (!da)
278 return NULL;
279
280 mp_filter_add_pin(da, MP_PIN_IN, "in");
281 mp_filter_add_pin(da, MP_PIN_OUT, "out");
282
283 da->log = mp_log_new(da, parent->log, NULL);
284
285 struct priv *priv = da->priv;
286 priv->public.f = da;
287
288 if (!init(da, codec, decoder)) {
289 talloc_free(da);
290 return NULL;
291 }
292 return &priv->public;
293 }
294
add_decoders(struct mp_decoder_list * list)295 static void add_decoders(struct mp_decoder_list *list)
296 {
297 mp_add_lavc_decoders(list, AVMEDIA_TYPE_AUDIO);
298 }
299
300 const struct mp_decoder_fns ad_lavc = {
301 .create = create,
302 .add_decoders = add_decoders,
303 };
304