]> git.sesse.net Git - ffmpeg/blobdiff - libavcodec/mpegvideo_parser.c
lavc: add a null bitstream filter
[ffmpeg] / libavcodec / mpegvideo_parser.c
index 2ccb9fff2c7072b64417a4984e11d6737648cb22..27f2985509c0aeb53c37e92bad6ef9096da21508 100644 (file)
@@ -1,51 +1,60 @@
 /*
- * MPEG1 / MPEG2 video parser
+ * MPEG-1 / MPEG-2 video parser
  * Copyright (c) 2000,2001 Fabrice Bellard
  * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
  *
- * This file is part of FFmpeg.
+ * This file is part of Libav.
  *
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
- * FFmpeg is distributed in the hope that it will be useful,
+ * Libav is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
+ * License along with Libav; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include "parser.h"
-#include "mpegvideo.h"
+#include "mpeg12.h"
+#include "internal.h"
+
+struct MpvParseContext {
+    ParseContext pc;
+    AVRational frame_rate;
+    int progressive_sequence;
+    int width, height;
+};
+
 
 static void mpegvideo_extract_headers(AVCodecParserContext *s,
                                       AVCodecContext *avctx,
                                       const uint8_t *buf, int buf_size)
 {
-    ParseContext1 *pc = s->priv_data;
-    const uint8_t *buf_end;
-    const uint8_t *buf_start= buf;
+    struct MpvParseContext *pc = s->priv_data;
+    const uint8_t *buf_end = buf + buf_size;
     uint32_t start_code;
     int frame_rate_index, ext_type, bytes_left;
     int frame_rate_ext_n, frame_rate_ext_d;
-    int picture_structure, top_field_first, repeat_first_field, progressive_frame;
+    int top_field_first, repeat_first_field, progressive_frame;
     int horiz_size_ext, vert_size_ext, bit_rate_ext;
+    int did_set_size=0;
+    int chroma_format;
+    enum AVPixelFormat pix_fmt = AV_PIX_FMT_NONE;
 //FIXME replace the crap with get_bits()
     s->repeat_pict = 0;
-    buf_end = buf + buf_size;
+
     while (buf < buf_end) {
         start_code= -1;
-        buf= ff_find_start_code(buf, buf_end, &start_code);
+        buf= avpriv_find_start_code(buf, buf_end, &start_code);
         bytes_left = buf_end - buf;
         switch(start_code) {
         case PICTURE_START_CODE:
-            ff_fetch_timestamp(s, buf-buf_start-4, 1);
-
             if (bytes_left >= 2) {
                 s->pict_type = (buf[1] >> 3) & 7;
             }
@@ -54,13 +63,15 @@ static void mpegvideo_extract_headers(AVCodecParserContext *s,
             if (bytes_left >= 7) {
                 pc->width  = (buf[0] << 4) | (buf[1] >> 4);
                 pc->height = ((buf[1] & 0x0f) << 8) | buf[2];
-                avcodec_set_dimensions(avctx, pc->width, pc->height);
+                if(!avctx->width || !avctx->height || !avctx->coded_width || !avctx->coded_height){
+                    ff_set_dimensions(avctx, pc->width, pc->height);
+                    did_set_size=1;
+                }
+                pix_fmt = AV_PIX_FMT_YUV420P;
                 frame_rate_index = buf[3] & 0xf;
-                pc->frame_rate.den = avctx->time_base.den = ff_frame_rate_tab[frame_rate_index].num;
-                pc->frame_rate.num = avctx->time_base.num = ff_frame_rate_tab[frame_rate_index].den;
+                pc->frame_rate = avctx->framerate = ff_mpeg12_frame_rate_tab[frame_rate_index];
                 avctx->bit_rate = ((buf[4]<<10) | (buf[5]<<2) | (buf[6]>>6))*400;
-                avctx->codec_id = CODEC_ID_MPEG1VIDEO;
-                avctx->sub_id = 1;
+                avctx->codec_id = AV_CODEC_ID_MPEG1VIDEO;
             }
             break;
         case EXT_START_CODE:
@@ -77,19 +88,25 @@ static void mpegvideo_extract_headers(AVCodecParserContext *s,
                         pc->progressive_sequence = buf[1] & (1 << 3);
                         avctx->has_b_frames= !(buf[5] >> 7);
 
+                        chroma_format = (buf[1] >> 1) & 3;
+                        switch (chroma_format) {
+                        case 1: pix_fmt = AV_PIX_FMT_YUV420P; break;
+                        case 2: pix_fmt = AV_PIX_FMT_YUV422P; break;
+                        case 3: pix_fmt = AV_PIX_FMT_YUV444P; break;
+                        }
+
                         pc->width  |=(horiz_size_ext << 12);
                         pc->height |=( vert_size_ext << 12);
                         avctx->bit_rate += (bit_rate_ext << 18) * 400;
-                        avcodec_set_dimensions(avctx, pc->width, pc->height);
-                        avctx->time_base.den = pc->frame_rate.den * (frame_rate_ext_n + 1) * 2;
-                        avctx->time_base.num = pc->frame_rate.num * (frame_rate_ext_d + 1);
-                        avctx->codec_id = CODEC_ID_MPEG2VIDEO;
-                        avctx->sub_id = 2; /* forces MPEG2 */
+                        if(did_set_size)
+                            ff_set_dimensions(avctx, pc->width, pc->height);
+                        avctx->framerate.num = pc->frame_rate.num * (frame_rate_ext_n + 1) * 2;
+                        avctx->framerate.den = pc->frame_rate.den * (frame_rate_ext_d + 1);
+                        avctx->codec_id = AV_CODEC_ID_MPEG2VIDEO;
                     }
                     break;
                 case 0x8: /* picture coding extension */
                     if (bytes_left >= 5) {
-                        picture_structure = buf[2]&3;
                         top_field_first = buf[3] & (1 << 7);
                         repeat_first_field = buf[3] & (1 << 1);
                         progressive_frame = buf[4] & (1 << 7);
@@ -106,6 +123,14 @@ static void mpegvideo_extract_headers(AVCodecParserContext *s,
                                 s->repeat_pict = 2;
                             }
                         }
+
+                        if (!pc->progressive_sequence) {
+                            if (top_field_first)
+                                s->field_order = AV_FIELD_TT;
+                            else
+                                s->field_order = AV_FIELD_BB;
+                        } else
+                            s->field_order = AV_FIELD_PROGRESSIVE;
                     }
                     break;
                 }
@@ -123,6 +148,19 @@ static void mpegvideo_extract_headers(AVCodecParserContext *s,
         }
     }
  the_end: ;
+
+    if (pix_fmt != AV_PIX_FMT_NONE) {
+        s->format = pix_fmt;
+        s->width  = pc->width;
+        s->height = pc->height;
+        s->coded_width  = FFALIGN(pc->width,  16);
+        s->coded_height = FFALIGN(pc->height, 16);
+    }
+
+#if FF_API_AVCTX_TIMEBASE
+    if (avctx->framerate.num)
+        avctx->time_base = av_inv_q(avctx->framerate);
+#endif
 }
 
 static int mpegvideo_parse(AVCodecParserContext *s,
@@ -130,14 +168,14 @@ static int mpegvideo_parse(AVCodecParserContext *s,
                            const uint8_t **poutbuf, int *poutbuf_size,
                            const uint8_t *buf, int buf_size)
 {
-    ParseContext1 *pc1 = s->priv_data;
+    struct MpvParseContext *pc1 = s->priv_data;
     ParseContext *pc= &pc1->pc;
     int next;
 
     if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){
         next= buf_size;
     }else{
-        next= ff_mpeg1_find_frame_end(pc, buf, buf_size);
+        next= ff_mpeg1_find_frame_end(pc, buf, buf_size, s);
 
         if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
             *poutbuf = NULL;
@@ -150,10 +188,8 @@ static int mpegvideo_parse(AVCodecParserContext *s,
        to have the full timing information. The time take by this
        function should be negligible for uncorrupted streams */
     mpegvideo_extract_headers(s, avctx, buf, buf_size);
-#if 0
-    printf("pict_type=%d frame_rate=%0.3f repeat_pict=%d\n",
-           s->pict_type, (double)avctx->time_base.den / avctx->time_base.num, s->repeat_pict);
-#endif
+    ff_dlog(NULL, "pict_type=%d frame_rate=%0.3f repeat_pict=%d\n",
+            s->pict_type, (double)avctx->time_base.den / avctx->time_base.num, s->repeat_pict);
 
     *poutbuf = buf;
     *poutbuf_size = buf_size;
@@ -174,10 +210,10 @@ static int mpegvideo_split(AVCodecContext *avctx,
     return 0;
 }
 
-AVCodecParser mpegvideo_parser = {
-    { CODEC_ID_MPEG1VIDEO, CODEC_ID_MPEG2VIDEO },
-    sizeof(ParseContext1),
-    NULL,
-    mpegvideo_parse,
-    ff_parse1_close,
+AVCodecParser ff_mpegvideo_parser = {
+    .codec_ids      = { AV_CODEC_ID_MPEG1VIDEO, AV_CODEC_ID_MPEG2VIDEO },
+    .priv_data_size = sizeof(struct MpvParseContext),
+    .parser_parse   = mpegvideo_parse,
+    .parser_close   = ff_parse_close,
+    .split          = mpegvideo_split,
 };