[FFmpeg-devel] [PATCH] IFF: Add the HAM stuff

Sebastian Vater cdgs.basty
Sun May 16 00:40:21 CEST 2010


Stefano Sabatini a ?crit :
> On date Saturday 2010-05-15 23:12:25 +0200, Sebastian Vater encoded:
>   
>
>> diff --git a/libavcodec/iff.c b/libavcodec/iff.c
>> index 3cdc964..0ff81be 100644
>> --- a/libavcodec/iff.c
>> +++ b/libavcodec/iff.c
>> @@ -30,10 +30,37 @@
>>  #include "get_bits.h"
>>  #include "iff.h"
>>  
>> +// TODO: masking bits
>> +#define MASK_NONE                  0
>> +#define MASK_HAS_MASK              1
>> +#define MASK_HAS_TRANSPARENT_COLOR 2
>> +#define MASK_LASSO                 3
>> +
>> +/**
>> + * Gets the actual packet data after video properties which contains
>> + * the raw data beyond the IFF extra context.
>> + */
>> +#define GET_EXTRA_DATA(x) ((uint8_t *) (x)->data + AV_RB16((x)->data))
>> +
>> +/**
>> + * Gets the size of raw data beyond the IFF extra context. Please note
>> + * that any value < 2 of either IFF extra context or raw packet data
>> + * is considered as an illegal packet.
>> + */
>> +#define GET_EXTRA_SIZE(x) ((x)->size - AV_RB16((x)->data))
>> +
>>  typedef struct {
>>      AVFrame frame;
>>      int planesize;
>>      uint8_t * planebuf;
>> +    uint8_t * ham_buf;      ///< Temporary buffer for planar to chunky conversation
>> +    uint32_t *ham_palbuf;   ///< HAM decode table
>> +    unsigned  compression;  ///< Delta compression method used
>> +    unsigned  bpp;          ///< Bits per plane to decode
>> +    unsigned  ham;          ///< 0 if non-HAM or number of hold bits (6 for bpp > 6, 4 otherwise)
>> +    unsigned  flags;        ///< 1 for EHB, 0 is no extra half darkening
>> +    unsigned  masking;      ///< TODO: Masking method used
>> +    unsigned  transparency; ///< TODO: Transparency color index in palette
>>  } IffContext;
>>  
>>  #define LUT8_PART(plane, v)                             \
>> @@ -219,6 +246,125 @@ static void decodeplane32(uint32_t *dst, const uint8_t *buf, int buf_size, int p
>>      } while (--buf_size);
>>  }
>>  
>> +#define DECODE_HAM_PLANE32(x)       \
>> +    first       = buf[x] << 1;      \
>> +    second      = buf[(x)+1] << 1;  \
>> +    delta      &= pal[first++];     \
>> +    delta      |= pal[first];       \
>> +    dst[x]      = delta;            \
>> +    delta      &= pal[second++];    \
>> +    delta      |= pal[second];      \
>> +    dst[(x)+1]  = delta;
>> +
>> +/**
>> + * Converts one line of HAM6/8-encoded chunky buffer to 24bpp
>>     
>
> missing final dot.
>   

Fixed.

>   
>> + *
>> + * @param dst the destination 24bpp buffer
>> + * @param buf the source 8bpp chunky buffer
>> + * @param pal the HAM decode table
>> + * @param buf_size the plane size in bytes
>> + */
>> +static void decode_ham_plane32(uint32_t *dst, const uint8_t  *buf,
>> +                               const uint32_t *const pal, unsigned buf_size)
>> +{
>> +    uint32_t delta = 0;
>> +    do {
>> +        uint32_t first, second;
>> +        DECODE_HAM_PLANE32(0)
>> +        DECODE_HAM_PLANE32(2)
>> +        DECODE_HAM_PLANE32(4)
>> +        DECODE_HAM_PLANE32(6)
>> +        buf += 8;
>> +        dst += 8;
>> +    } while (--buf_size);
>> +}
>> +
>> +/**
>> + * Extracts the IFF extra context and updates internal
>> + * decoder structures.
>> + *
>> + * @param avctx the AVCodecContext where to extract extra context to
>> + * @param avpkt the AVPacket to extract extra context from
>> + *
>>     
>
> Nit+++: no need for this empty newline
>   

Which empty new line? They're just cosmetics like in the other
functions, too. So you see return value separated to args.

>   
>> + * @return returns error status. 0 is OK, error otherwise
>>     
>
> @return 0 in case of success, a negative error code otherwise
>   

Fixed.

>   
>> + */
>> +static int extract_header(AVCodecContext *const avctx,
>> +                          const AVPacket *const avpkt) {
>> +    IffContext *s = avctx->priv_data;
>> +    const uint8_t *buf = avpkt->data;
>> +    const unsigned buf_size = bytestream_get_be16(&buf);
>> +    if (buf_size <= 1 || (int) GET_EXTRA_SIZE(avpkt) <= 1) {
>> +        av_log(avctx, AV_LOG_ERROR,
>> +               "Invalid packet size received: %u -> video data offset: %d\n",
>> +               (unsigned) buf_size, (int) GET_EXTRA_SIZE(avpkt));
>> +        return AVERROR_INVALIDDATA;
>> +    }
>> +    if (buf_size > 8) {
>> +        s->compression  = bytestream_get_byte(&buf);
>> +        s->bpp          = bytestream_get_byte(&buf);
>> +        s->ham          = bytestream_get_byte(&buf);
>> +        s->flags        = bytestream_get_byte(&buf);
>> +        s->transparency = bytestream_get_be16(&buf);
>> +        s->masking      = bytestream_get_byte(&buf);
>> +    }
>> +
>> +    if (s->masking == MASK_HAS_TRANSPARENT_COLOR) {
>> +        av_log(avctx, AV_LOG_ERROR, "Transparency not supported\n");
>> +        return AVERROR_PATCHWELCOME;
>> +    } else if (s->masking != MASK_NONE) {
>> +        av_log(avctx, AV_LOG_ERROR, "Masking not supported\n");
>> +        return AVERROR_PATCHWELCOME;
>> +    }
>> +
>> +    av_freep(&s->ham_buf);
>> +    av_freep(&s->ham_palbuf);
>> +
>> +    if (s->ham) {
>> +        int i;
>> +        int count = FFMIN(avctx->extradata_size / 3, 1 << s->ham);
>> +        const unsigned mbits = 8 - s->ham;
>> +        s->ham_buf = av_malloc((s->planesize * 8) + FF_INPUT_BUFFER_PADDING_SIZE);
>> +        if (!s->ham_buf)
>> +            return AVERROR(ENOMEM);
>> +
>> +        s->ham_palbuf = av_malloc((8 * (1 << s->ham) * sizeof (uint32_t)) + FF_INPUT_BUFFER_PADDING_SIZE);
>> +        if (!s->ham_palbuf) {
>> +            av_freep(&s->ham_buf);
>> +            return AVERROR(ENOMEM);
>> +        }
>> +
>> +        if (count) { // HAM with color palette attached
>>     
>
>   
>> +            // prefill with black and palette and set take direct color mask to zero
>>     
>
> "set take" sounds weird
>   

Fixed.

>   
>>  /**
>>   * Decodes one complete byterun1 encoded line.
>>   *
>> @@ -256,31 +402,43 @@ static int decode_frame_ilbm(AVCodecContext *avctx,
>>                              AVPacket *avpkt)
>>  {
>>      IffContext *s = avctx->priv_data;
>> -    const uint8_t *buf = avpkt->data;
>> -    int buf_size = avpkt->size;
>> +    const uint8_t *buf = GET_EXTRA_DATA(avpkt);
>> +    int buf_size = GET_EXTRA_SIZE(avpkt);
>>      const uint8_t *buf_end = buf+buf_size;
>> -    int y, plane;
>> +    int y, plane, err;
>>  
>>      if (avctx->reget_buffer(avctx, &s->frame) < 0){
>>     
>
> Nit++: missing space after closing ")"
>   

Will do in a separate patch, since I'm not changing this line.

>   
>>          av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
>>          return -1;
>>     
>
> if ((err = ...) < 0) {
>    av_log(...)
>    return err;
> }
>   

Fixed.

>   
>>                  }
>> @@ -292,6 +450,13 @@ static int decode_frame_ilbm(AVCodecContext *avctx,
>>              memcpy(row, buf, FFMIN(avctx->width, buf_end - buf));
>>              buf += avctx->width;
>>          }
>> +    } else { // IFF-PBM: HAM to PIX_FMT_BGR32
>> +        for(y = 0; y < avctx->height; y++ ) {
>>     
>
> for_(
>   

Fixed.

>   
>> +        } else if (s->ham) { // HAM to PIX_FMT_BGR32
>> +            for(y = 0; y < avctx->height ; y++ ) {
>> +                uint8_t *row = &s->frame.data[0][y*s->frame.linesize[0]];
>> +                memset(s->ham_buf, 0, avctx->width);
>> +                for (plane = 0; plane < s->bpp; plane++) {
>> +                    buf = decode_byterun(s->planebuf, buf, buf_end, s->planesize);
>> +                    decodeplane8(s->ham_buf, s->planebuf, s->planesize, plane);
>> +                }
>> +                decode_ham_plane32((uint32_t *) row, s->ham_buf, s->ham_palbuf, s->planesize);
>> +            }
>>          } else { //PIX_FMT_BGR32
>>              for(y = 0; y < avctx->height ; y++ ) {
>>                  uint8_t *row = &s->frame.data[0][y*s->frame.linesize[0]];
>>                  memset(row, 0, avctx->width << 2);
>> -                for (plane = 0; plane < avctx->bits_per_coded_sample; plane++) {
>> +                for (plane = 0; plane < s->bpp; plane++) {
>>                      buf = decode_byterun(s->planebuf, buf, buf_end, s->planesize);
>>                      decodeplane32((uint32_t *) row, s->planebuf, s->planesize, plane);
>>                  }
>>              }
>>          }
>>     
>
> Note, this can be factorized (but not in this patch of course ;-)
>   

Okay, will do this when the HAM patch is in.

>   
>> -    } else {
>> +    } else if (avctx->pix_fmt == PIX_FMT_PAL8 || avctx->pix_fmt == PIX_FMT_GRAY8) { // IFF-PBM
>>          for(y = 0; y < avctx->height ; y++ ) {
>>              uint8_t *row = &s->frame.data[0][y*s->frame.linesize[0]];
>>              buf = decode_byterun(row, buf, buf_end, avctx->width);
>>          }
>> +    } else { // IFF-PBM: HAM to PIX_FMT_BGR32
>> +        for(y = 0; y < avctx->height ; y++ ) {
>>     
>
> Nit++: for_(, no space after y++
>   

Fixed.

>   
>> +/**
>> + * IFF extra video context. This data is prepended to actual
>> + * video pixel data, always stored in big-endian format.
>> + *
>> + * If you add new data here, always check check whether the packet you
>> + * receive is large enough (offset >= is actually large enough).
>> + *
>> + * uint16_t offset;       ///< Offset to add to get raw video pixel data
>> + * uint8_t  compression;  ///< Delta compression method used
>> + * uint8_t  bpp;          ///< Bits per plane to decode
>> + * uint8_t  ham;          ///< 0 if non-HAM or number of hold bits (6 for bpp > 6, 4 otherwise)
>> + * uint8_t  flags;        ///< TODO: 1 for EHB, 0 is no extra half darkening
>> + * uint16_t transparency; ///< TODO: Transparency color index in palette
>> + * uint8_t  masking;      ///< TODO: Masking method used
>> + */
>>     
>
> This doxy looks misplaced, seems like IffDemuxContext though but I see
> the types are different (maybe having uintX_t is preferable than
> using always unsigned).
>   

Fixed.

>   
>>  
>> +// screenmode bits
>> +#define CAMG_EHB 0x80    // Extra HalfBrite
>> +#define CAMG_HAM 0x800   // Hold And Modify
>> +
>> +/**
>> + * This number of bytes if added at the beginning of each AVPacket
>> + * which contain additional information about video properties
>> + * which has to be shared between demuxer and decoder also changeable
>> + * between frames.
>>     
>
> "... and decoder. This number may change between frames."
>
> looks more readable.
>   

Fixed.

>   
>> + */
>> +#define IFF_EXTRA_VIDEO_SIZE 9
>> +
>>  typedef enum {
>>      COMP_NONE,
>>      COMP_FIB,
>> @@ -77,6 +91,12 @@ typedef struct {
>>      uint32_t  body_size;
>>      uint32_t  sent_bytes;
>>      uint32_t  audio_frame_count;
>> +    unsigned  compression;  ///< Delta compression method used
>> +    unsigned  bpp;          ///< Bits per plane to decode
>> +    unsigned  ham;          ///< 0 if non-HAM or number of hold bits (6 for bpp > 6, 4 otherwise)
>> +    unsigned  flags;        ///< 1 for EHB, 0 is no extra half darkening
>> +    unsigned  masking;      ///< Masking method used
>> +    unsigned  transparency; ///< Transparency color index in palette
>>     
>
> Nit++: no need for capitalization of the field doxies, as they are
> non-complete sentences.
>   

Fixed.

>   
>>  } IffDemuxContext;
>>  
>>  
>> @@ -129,6 +149,9 @@ static int iff_read_header(AVFormatContext *s,
>>      AVStream *st;
>>      uint32_t chunk_id, data_size;
>>      int compression = -1;
>> +    uint32_t screenmode = 0;
>> +    unsigned transparency = 0;
>> +    unsigned masking = 0; // MASK_NONE
>>     
>
> directly use the macro value
>   

Fixed.

>>  
>>      case AVMEDIA_TYPE_VIDEO:
>> +        iff->compression  = compression;
>> +        iff->bpp          = st->codec->bits_per_coded_sample;
>> +        if ((screenmode & CAMG_HAM) &&
>>     
>
>   
>> +             st->codec->bits_per_coded_sample <= 8) {
>> +            iff->ham          = st->codec->bits_per_coded_sample > 6 ? 6 : 4;
>>     
>
> iff->bpp is shorter.
>   

Fixed.

>
>> +        iff->masking      = masking;
>> +        iff->transparency = transparency;
>> +
>>          switch (compression) {
>>          case BITMAP_RAW:
>>              st->codec->codec_id = CODEC_ID_IFF_ILBM;
>> @@ -294,7 +338,21 @@ static int iff_read_packet(AVFormatContext *s,
>>          }
>>          interleave_stereo(sample_buffer, pkt->data, PACKET_SIZE);
>>      } else if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
>> -        ret = av_get_packet(pb, pkt, iff->body_size);
>> +        uint8_t *buf;
>> +
>> +        if(av_new_packet(pkt, iff->body_size + IFF_EXTRA_VIDEO_SIZE) < 0) {
>>     
>
> if_(
>   

Fixed.

>   
>> +            return AVERROR(ENOMEM);
>> +        }
>> +
>> +        buf = pkt->data;
>> +        bytestream_put_be16(&buf, IFF_EXTRA_VIDEO_SIZE);
>> +        bytestream_put_byte(&buf, iff->compression);
>> +        bytestream_put_byte(&buf, iff->bpp);
>> +        bytestream_put_byte(&buf, iff->ham);
>> +        bytestream_put_byte(&buf, iff->flags);
>> +        bytestream_put_be16(&buf, iff->transparency);
>> +        bytestream_put_byte(&buf, iff->masking);
>> +        ret = get_buffer(pb, buf, iff->body_size);
>>      } else {
>>          ret = av_get_packet(pb, pkt, PACKET_SIZE);
>>      }
>>     
-- 

Best regards,
                   :-) Basty/CDGS (-:

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